diff --git a/src/test/compile-fail/associated-types-unsized.rs b/src/test/compile-fail/associated-types-unsized.rs
index e4b97ab5933ce..a32d4de77557b 100644
--- a/src/test/compile-fail/associated-types-unsized.rs
+++ b/src/test/compile-fail/associated-types-unsized.rs
@@ -14,7 +14,7 @@ trait Get {
 }
 
 fn foo<T:Get>(t: T) {
-    let x = t.get(); //~ ERROR the trait `core::marker::Sized` is not implemented
+    let x = t.get(); //~ ERROR the trait `std::marker::Sized` is not implemented
 }
 
 fn main() {
diff --git a/src/test/compile-fail/bad-const-type.rs b/src/test/compile-fail/bad-const-type.rs
index a9e5c957b89d4..f05c8c31f1024 100644
--- a/src/test/compile-fail/bad-const-type.rs
+++ b/src/test/compile-fail/bad-const-type.rs
@@ -10,8 +10,8 @@
 
 static i: String = 10;
 //~^ ERROR mismatched types
-//~| expected `collections::string::String`
+//~| expected `std::string::String`
 //~| found `_`
-//~| expected struct `collections::string::String`
+//~| expected struct `std::string::String`
 //~| found integral variable
 fn main() { println!("{}", i); }
diff --git a/src/test/compile-fail/bad-method-typaram-kind.rs b/src/test/compile-fail/bad-method-typaram-kind.rs
index 2129d4fbd5055..224187c8ac4cd 100644
--- a/src/test/compile-fail/bad-method-typaram-kind.rs
+++ b/src/test/compile-fail/bad-method-typaram-kind.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 fn foo<T:'static>() {
-    1.bar::<T>(); //~ ERROR `core::marker::Send` is not implemented
+    1.bar::<T>(); //~ ERROR `std::marker::Send` is not implemented
 }
 
 trait bar {
diff --git a/src/test/compile-fail/bad-sized.rs b/src/test/compile-fail/bad-sized.rs
index bfe9d7403399d..e9dd0585fa9e9 100644
--- a/src/test/compile-fail/bad-sized.rs
+++ b/src/test/compile-fail/bad-sized.rs
@@ -12,7 +12,7 @@ trait Trait {}
 
 pub fn main() {
     let x: Vec<Trait + Sized> = Vec::new();
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
-    //~| ERROR the trait `core::marker::Sized` is not implemented
-    //~| ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
+    //~| ERROR the trait `std::marker::Sized` is not implemented
+    //~| ERROR the trait `std::marker::Sized` is not implemented
 }
diff --git a/src/test/compile-fail/binop-bitxor-str.rs b/src/test/compile-fail/binop-bitxor-str.rs
index 58cacc0b9f333..3f26e3ce904cf 100644
--- a/src/test/compile-fail/binop-bitxor-str.rs
+++ b/src/test/compile-fail/binop-bitxor-str.rs
@@ -8,6 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:`^` cannot be applied to type `collections::string::String`
+// error-pattern:`^` cannot be applied to type `std::string::String`
 
 fn main() { let x = "a".to_string() ^ "b".to_string(); }
diff --git a/src/test/compile-fail/builtin-superkinds-double-superkind.rs b/src/test/compile-fail/builtin-superkinds-double-superkind.rs
index cd215a7373780..e1bcc63fb2fed 100644
--- a/src/test/compile-fail/builtin-superkinds-double-superkind.rs
+++ b/src/test/compile-fail/builtin-superkinds-double-superkind.rs
@@ -13,9 +13,9 @@
 
 trait Foo : Send+Sync { }
 
-impl <T: Sync+'static> Foo for (T,) { } //~ ERROR the trait `core::marker::Send` is not implemented
+impl <T: Sync+'static> Foo for (T,) { } //~ ERROR the trait `std::marker::Send` is not implemented
 
-impl <T: Send> Foo for (T,T) { } //~ ERROR the trait `core::marker::Sync` is not implemented
+impl <T: Send> Foo for (T,T) { } //~ ERROR the trait `std::marker::Sync` is not implemented
 
 impl <T: Send+Sync> Foo for (T,T,T) { } // (ok)
 
diff --git a/src/test/compile-fail/builtin-superkinds-in-metadata.rs b/src/test/compile-fail/builtin-superkinds-in-metadata.rs
index 138fcfa8b64fe..5e2ba7a3b9d46 100644
--- a/src/test/compile-fail/builtin-superkinds-in-metadata.rs
+++ b/src/test/compile-fail/builtin-superkinds-in-metadata.rs
@@ -22,6 +22,6 @@ struct X<T>(T);
 impl <T:Sync> RequiresShare for X<T> { }
 
 impl <T:Sync+'static> RequiresRequiresShareAndSend for X<T> { }
-//~^ ERROR the trait `core::marker::Send` is not implemented
+//~^ ERROR the trait `std::marker::Send` is not implemented
 
 fn main() { }
diff --git a/src/test/compile-fail/builtin-superkinds-simple.rs b/src/test/compile-fail/builtin-superkinds-simple.rs
index c3fb6a1be8797..7c9c0df412a40 100644
--- a/src/test/compile-fail/builtin-superkinds-simple.rs
+++ b/src/test/compile-fail/builtin-superkinds-simple.rs
@@ -14,6 +14,6 @@
 trait Foo : Send { }
 
 impl Foo for std::rc::Rc<i8> { }
-//~^ ERROR the trait `core::marker::Send` is not implemented
+//~^ ERROR the trait `std::marker::Send` is not implemented
 
 fn main() { }
diff --git a/src/test/compile-fail/builtin-superkinds-typaram-not-send.rs b/src/test/compile-fail/builtin-superkinds-typaram-not-send.rs
index 534bb6d37ec39..13ad13223466b 100644
--- a/src/test/compile-fail/builtin-superkinds-typaram-not-send.rs
+++ b/src/test/compile-fail/builtin-superkinds-typaram-not-send.rs
@@ -12,6 +12,6 @@
 
 trait Foo : Send { }
 
-impl <T: Sync+'static> Foo for T { } //~ ERROR the trait `core::marker::Send` is not implemented
+impl <T: Sync+'static> Foo for T { } //~ ERROR the trait `std::marker::Send` is not implemented
 
 fn main() { }
diff --git a/src/test/compile-fail/cast-rfc0401.rs b/src/test/compile-fail/cast-rfc0401.rs
index b458334006a51..9653a1357efa0 100644
--- a/src/test/compile-fail/cast-rfc0401.rs
+++ b/src/test/compile-fail/cast-rfc0401.rs
@@ -91,7 +91,7 @@ fn main()
     let _ = 42usize as *const [u8]; //~ ERROR casting
     let _ = v as *const [u8]; //~ ERROR cannot cast
     let _ = fat_v as *const Foo;
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `[u8]`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `[u8]`
     //~^^ HELP run `rustc --explain E0277` to see a detailed explanation
     //~^^^ NOTE `[u8]` does not have a constant size known at compile-time
     //~^^^^ NOTE required for the cast to the object type `Foo`
@@ -106,7 +106,7 @@ fn main()
 
     let a : *const str = "hello";
     let _ = a as *const Foo;
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `str`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `str`
     //~^^ HELP run `rustc --explain E0277` to see a detailed explanation
     //~^^^ NOTE `str` does not have a constant size known at compile-time
     //~^^^^ NOTE required for the cast to the object type `Foo`
diff --git a/src/test/compile-fail/closure-bounds-cant-promote-superkind-in-struct.rs b/src/test/compile-fail/closure-bounds-cant-promote-superkind-in-struct.rs
index b88040cbd54a6..40085d8137893 100644
--- a/src/test/compile-fail/closure-bounds-cant-promote-superkind-in-struct.rs
+++ b/src/test/compile-fail/closure-bounds-cant-promote-superkind-in-struct.rs
@@ -13,7 +13,7 @@ struct X<F> where F: FnOnce() + 'static + Send {
 }
 
 fn foo<F>(blk: F) -> X<F> where F: FnOnce() + 'static {
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type
     return X { field: blk };
 }
 
diff --git a/src/test/compile-fail/closure-bounds-subtype.rs b/src/test/compile-fail/closure-bounds-subtype.rs
index fadaa84f19db5..c8fe4a1b8d268 100644
--- a/src/test/compile-fail/closure-bounds-subtype.rs
+++ b/src/test/compile-fail/closure-bounds-subtype.rs
@@ -21,7 +21,7 @@ fn give_any<F>(f: F) where F: FnOnce() {
 
 fn give_owned<F>(f: F) where F: FnOnce() + Send {
     take_any(f);
-    take_const_owned(f); //~ ERROR the trait `core::marker::Sync` is not implemented for the type
+    take_const_owned(f); //~ ERROR the trait `std::marker::Sync` is not implemented for the type
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/coherence-conflicting-negative-trait-impl.rs b/src/test/compile-fail/coherence-conflicting-negative-trait-impl.rs
index c123e381ab7d7..afc3b8d4ccddc 100644
--- a/src/test/compile-fail/coherence-conflicting-negative-trait-impl.rs
+++ b/src/test/compile-fail/coherence-conflicting-negative-trait-impl.rs
@@ -17,10 +17,10 @@ struct TestType<T>(::std::marker::PhantomData<T>);
 unsafe impl<T: MyTrait+'static> Send for TestType<T> {}
 
 impl<T: MyTrait> !Send for TestType<T> {}
-//~^ ERROR conflicting implementations of trait `core::marker::Send`
+//~^ ERROR conflicting implementations of trait `std::marker::Send`
 
 unsafe impl<T:'static> Send for TestType<T> {}
-//~^ ERROR error: conflicting implementations of trait `core::marker::Send`
+//~^ ERROR error: conflicting implementations of trait `std::marker::Send`
 
 impl !Send for TestType<i32> {}
 
diff --git a/src/test/compile-fail/deriving-no-inner-impl-error-message.rs b/src/test/compile-fail/deriving-no-inner-impl-error-message.rs
index ac63cc27da1ee..4fc922d32a0e7 100644
--- a/src/test/compile-fail/deriving-no-inner-impl-error-message.rs
+++ b/src/test/compile-fail/deriving-no-inner-impl-error-message.rs
@@ -18,7 +18,7 @@ struct E {
 #[derive(Clone)]
 struct C {
     x: NoCloneOrEq
-    //~^ ERROR the trait `core::clone::Clone` is not implemented for the type `NoCloneOrEq`
+    //~^ ERROR the trait `std::clone::Clone` is not implemented for the type `NoCloneOrEq`
 }
 
 
diff --git a/src/test/compile-fail/deriving-span-Default-struct.rs b/src/test/compile-fail/deriving-span-Default-struct.rs
index ac718519fe672..e70a1613dc201 100644
--- a/src/test/compile-fail/deriving-span-Default-struct.rs
+++ b/src/test/compile-fail/deriving-span-Default-struct.rs
@@ -17,7 +17,7 @@ struct Error;
 
 #[derive(Default)]
 struct Struct {
-    x: Error //~ ERROR `core::default::Default` is not implemented
+    x: Error //~ ERROR `std::default::Default` is not implemented
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/destructure-trait-ref.rs b/src/test/compile-fail/destructure-trait-ref.rs
index 08db643df00e4..3c642bd8b7058 100644
--- a/src/test/compile-fail/destructure-trait-ref.rs
+++ b/src/test/compile-fail/destructure-trait-ref.rs
@@ -35,7 +35,7 @@ fn main() {
     // n == m
     let &x = &1isize as &T;      //~ ERROR type `&T` cannot be dereferenced
     let &&x = &(&1isize as &T);  //~ ERROR type `&T` cannot be dereferenced
-    let box x = box 1isize as Box<T>; //~ ERROR the trait `core::marker::Sized` is not implemented
+    let box x = box 1isize as Box<T>; //~ ERROR the trait `std::marker::Sized` is not implemented
 
     // n > m
     let &&x = &1isize as &T;
diff --git a/src/test/compile-fail/dropck_no_diverge_on_nonregular_3.rs b/src/test/compile-fail/dropck_no_diverge_on_nonregular_3.rs
index f7eb6e10ca788..45531666ecf5d 100644
--- a/src/test/compile-fail/dropck_no_diverge_on_nonregular_3.rs
+++ b/src/test/compile-fail/dropck_no_diverge_on_nonregular_3.rs
@@ -39,8 +39,8 @@ enum Wrapper<T:'static> {
 }
 
 fn main() {
-    let w = //~ ERROR overflow while adding drop-check rules for core::option
+    let w = //~ ERROR overflow while adding drop-check rules for std::option
         Some(Wrapper::Simple::<u32>);
-    //~^ ERROR overflow while adding drop-check rules for core::option::Option
+    //~^ ERROR overflow while adding drop-check rules for std::option::Option
     //~| ERROR overflow while adding drop-check rules for Wrapper
 }
diff --git a/src/test/compile-fail/dst-bad-assign-2.rs b/src/test/compile-fail/dst-bad-assign-2.rs
index 8441f3a99e1aa..110413cd32229 100644
--- a/src/test/compile-fail/dst-bad-assign-2.rs
+++ b/src/test/compile-fail/dst-bad-assign-2.rs
@@ -44,5 +44,5 @@ pub fn main() {
     // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
     let z: Box<ToBar> = Box::new(Bar1 {f: 36});
     f5.ptr = *z;
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
 }
diff --git a/src/test/compile-fail/dst-bad-assign.rs b/src/test/compile-fail/dst-bad-assign.rs
index d3029bc6a9980..d4221adfa2ace 100644
--- a/src/test/compile-fail/dst-bad-assign.rs
+++ b/src/test/compile-fail/dst-bad-assign.rs
@@ -49,5 +49,5 @@ pub fn main() {
     //~| found `Bar1`
     //~| expected trait ToBar
     //~| found struct `Bar1`
-    //~| ERROR the trait `core::marker::Sized` is not implemented for the type `ToBar`
+    //~| ERROR the trait `std::marker::Sized` is not implemented for the type `ToBar`
 }
diff --git a/src/test/compile-fail/dst-bad-deep.rs b/src/test/compile-fail/dst-bad-deep.rs
index f90baafef3ffa..9e23b6ea44e3e 100644
--- a/src/test/compile-fail/dst-bad-deep.rs
+++ b/src/test/compile-fail/dst-bad-deep.rs
@@ -21,5 +21,5 @@ pub fn main() {
     let f: Fat<[isize; 3]> = Fat { ptr: [5, 6, 7] };
     let g: &Fat<[isize]> = &f;
     let h: &Fat<Fat<[isize]>> = &Fat { ptr: *g };
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
 }
diff --git a/src/test/compile-fail/dst-object-from-unsized-type.rs b/src/test/compile-fail/dst-object-from-unsized-type.rs
index da667dcb1e882..68e6bc0ed7654 100644
--- a/src/test/compile-fail/dst-object-from-unsized-type.rs
+++ b/src/test/compile-fail/dst-object-from-unsized-type.rs
@@ -16,22 +16,22 @@ impl Foo for [u8] {}
 
 fn test1<T: ?Sized + Foo>(t: &T) {
     let u: &Foo = t;
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `T`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `T`
 }
 
 fn test2<T: ?Sized + Foo>(t: &T) {
     let v: &Foo = t as &Foo;
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `T`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `T`
 }
 
 fn test3() {
     let _: &[&Foo] = &["hi"];
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `str`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `str`
 }
 
 fn test4(x: &[u8]) {
     let _: &Foo = x as &Foo;
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `[u8]`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `[u8]`
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/dst-sized-trait-param.rs b/src/test/compile-fail/dst-sized-trait-param.rs
index 3436c8d488c70..0241c207c9df8 100644
--- a/src/test/compile-fail/dst-sized-trait-param.rs
+++ b/src/test/compile-fail/dst-sized-trait-param.rs
@@ -15,9 +15,9 @@
 trait Foo<T> : Sized { fn take(self, x: &T) { } } // Note: T is sized
 
 impl Foo<[isize]> for usize { }
-//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `[isize]`
+//~^ ERROR the trait `std::marker::Sized` is not implemented for the type `[isize]`
 
 impl Foo<isize> for [usize] { }
-//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `[usize]`
+//~^ ERROR the trait `std::marker::Sized` is not implemented for the type `[usize]`
 
 pub fn main() { }
diff --git a/src/test/compile-fail/error-should-say-copy-not-pod.rs b/src/test/compile-fail/error-should-say-copy-not-pod.rs
index d79b3f472d06b..14fe14ae3679b 100644
--- a/src/test/compile-fail/error-should-say-copy-not-pod.rs
+++ b/src/test/compile-fail/error-should-say-copy-not-pod.rs
@@ -13,5 +13,5 @@
 fn check_bound<T:Copy>(_: T) {}
 
 fn main() {
-    check_bound("nocopy".to_string()); //~ ERROR the trait `core::marker::Copy` is not implemented
+    check_bound("nocopy".to_string()); //~ ERROR the trait `std::marker::Copy` is not implemented
 }
diff --git a/src/test/compile-fail/extern-wrong-value-type.rs b/src/test/compile-fail/extern-wrong-value-type.rs
index d1abed9b2627c..8437ff766919b 100644
--- a/src/test/compile-fail/extern-wrong-value-type.rs
+++ b/src/test/compile-fail/extern-wrong-value-type.rs
@@ -17,6 +17,6 @@ fn main() {
     // extern functions are extern "C" fn
     let _x: extern "C" fn() = f; // OK
     is_fn(f);
-    //~^ ERROR the trait `core::ops::Fn<()>` is not implemented for the type `extern "C" fn()
-    //~| ERROR the trait `core::ops::FnOnce<()>` is not implemented for the type `extern "C" fn()
+    //~^ ERROR the trait `std::ops::Fn<()>` is not implemented for the type `extern "C" fn()
+    //~| ERROR the trait `std::ops::FnOnce<()>` is not implemented for the type `extern "C" fn()
 }
diff --git a/src/test/compile-fail/fn-item-type.rs b/src/test/compile-fail/fn-item-type.rs
index 949000dfed6ac..c90a7113f1b41 100644
--- a/src/test/compile-fail/fn-item-type.rs
+++ b/src/test/compile-fail/fn-item-type.rs
@@ -34,10 +34,10 @@ fn main() {
 
     eq(bar::<String>, bar::<Vec<u8>>);
     //~^ ERROR mismatched types
-    //~|  expected `fn(isize) -> isize {bar::<collections::string::String>}`
-    //~|  found `fn(isize) -> isize {bar::<collections::vec::Vec<u8>>}`
-    //~|  expected struct `collections::string::String`
-    //~|  found struct `collections::vec::Vec`
+    //~|  expected `fn(isize) -> isize {bar::<std::string::String>}`
+    //~|  found `fn(isize) -> isize {bar::<std::vec::Vec<u8>>}`
+    //~|  expected struct `std::string::String`
+    //~|  found struct `std::vec::Vec`
 
     // Make sure we distinguish between trait methods correctly.
     eq(<u8 as Foo>::foo, <u16 as Foo>::foo);
diff --git a/src/test/compile-fail/fn-trait-formatting.rs b/src/test/compile-fail/fn-trait-formatting.rs
index 6433255bd4d2f..6309beaf4b531 100644
--- a/src/test/compile-fail/fn-trait-formatting.rs
+++ b/src/test/compile-fail/fn-trait-formatting.rs
@@ -17,23 +17,23 @@ fn main() {
     let _: () = (box |_: isize| {}) as Box<FnOnce(isize)>;
     //~^ ERROR mismatched types
     //~| expected `()`
-    //~| found `Box<core::ops::FnOnce(isize)>`
+    //~| found `Box<std::ops::FnOnce(isize)>`
     //~| expected ()
     //~| found box
     let _: () = (box |_: isize, isize| {}) as Box<Fn(isize, isize)>;
     //~^ ERROR mismatched types
     //~| expected `()`
-    //~| found `Box<core::ops::Fn(isize, isize)>`
+    //~| found `Box<std::ops::Fn(isize, isize)>`
     //~| expected ()
     //~| found box
     let _: () = (box || -> isize { unimplemented!() }) as Box<FnMut() -> isize>;
     //~^ ERROR mismatched types
     //~| expected `()`
-    //~| found `Box<core::ops::FnMut() -> isize>`
+    //~| found `Box<std::ops::FnMut() -> isize>`
     //~| expected ()
     //~| found box
 
     needs_fn(1);
-    //~^ ERROR `core::ops::Fn<(isize,)>`
-    //~| ERROR `core::ops::FnOnce<(isize,)>`
+    //~^ ERROR `std::ops::Fn<(isize,)>`
+    //~| ERROR `std::ops::FnOnce<(isize,)>`
 }
diff --git a/src/test/compile-fail/for-loop-bogosity.rs b/src/test/compile-fail/for-loop-bogosity.rs
index c77683045170e..de4dd422d4ffc 100644
--- a/src/test/compile-fail/for-loop-bogosity.rs
+++ b/src/test/compile-fail/for-loop-bogosity.rs
@@ -24,7 +24,7 @@ pub fn main() {
         x: 1,
         y: 2,
     };
-    for x in bogus { //~ ERROR `core::iter::Iterator` is not implemented for the type `MyStruct`
+    for x in bogus { //~ ERROR `std::iter::Iterator` is not implemented for the type `MyStruct`
         drop(x);
     }
 }
diff --git a/src/test/compile-fail/fully-qualified-type-name1.rs b/src/test/compile-fail/fully-qualified-type-name1.rs
index 029acbff9c333..fb787e8572c20 100644
--- a/src/test/compile-fail/fully-qualified-type-name1.rs
+++ b/src/test/compile-fail/fully-qualified-type-name1.rs
@@ -14,8 +14,8 @@ fn main() {
     let x: Option<usize>;
     x = 5;
     //~^ ERROR mismatched types
-    //~| expected `core::option::Option<usize>`
+    //~| expected `std::option::Option<usize>`
     //~| found `_`
-    //~| expected enum `core::option::Option`
+    //~| expected enum `std::option::Option`
     //~| found integral variable
 }
diff --git a/src/test/compile-fail/fully-qualified-type-name4.rs b/src/test/compile-fail/fully-qualified-type-name4.rs
index d6d668b366aa3..9242849efc746 100644
--- a/src/test/compile-fail/fully-qualified-type-name4.rs
+++ b/src/test/compile-fail/fully-qualified-type-name4.rs
@@ -15,9 +15,9 @@ use std::option::Option;
 fn bar(x: usize) -> Option<usize> {
     return x;
     //~^ ERROR mismatched types
-    //~| expected `core::option::Option<usize>`
+    //~| expected `std::option::Option<usize>`
     //~| found `usize`
-    //~| expected enum `core::option::Option`
+    //~| expected enum `std::option::Option`
     //~| found usize
 }
 
diff --git a/src/test/compile-fail/generic-type-params-name-repr.rs b/src/test/compile-fail/generic-type-params-name-repr.rs
index a452cd35f943f..adf9a98a05c2d 100644
--- a/src/test/compile-fail/generic-type-params-name-repr.rs
+++ b/src/test/compile-fail/generic-type-params-name-repr.rs
@@ -38,13 +38,13 @@ fn main() {
     // Including cases where the default is using previous type params.
     let _: HashMap<String, isize> = ();
     //~^ ERROR mismatched types
-    //~| expected `HashMap<collections::string::String, isize>`
+    //~| expected `HashMap<std::string::String, isize>`
     //~| found `()`
     //~| expected struct `HashMap`
     //~| found ()
     let _: HashMap<String, isize, Hash<String>> = ();
     //~^ ERROR mismatched types
-    //~| expected `HashMap<collections::string::String, isize>`
+    //~| expected `HashMap<std::string::String, isize>`
     //~| found `()`
     //~| expected struct `HashMap`
     //~| found ()
diff --git a/src/test/compile-fail/ifmt-unimpl.rs b/src/test/compile-fail/ifmt-unimpl.rs
index 948040496bd39..19e019b58bc78 100644
--- a/src/test/compile-fail/ifmt-unimpl.rs
+++ b/src/test/compile-fail/ifmt-unimpl.rs
@@ -10,5 +10,5 @@
 
 fn main() {
     format!("{:X}", "3");
-    //~^ ERROR: the trait `core::fmt::UpperHex` is not implemented
+    //~^ ERROR: the trait `std::fmt::UpperHex` is not implemented
 }
diff --git a/src/test/compile-fail/indexing-requires-a-uint.rs b/src/test/compile-fail/indexing-requires-a-uint.rs
index 3d3b7bc1bcb43..8143ef84467ec 100644
--- a/src/test/compile-fail/indexing-requires-a-uint.rs
+++ b/src/test/compile-fail/indexing-requires-a-uint.rs
@@ -13,7 +13,7 @@
 
 fn main() {
     fn bar<T>(_: T) {}
-    [0][0u8]; //~ ERROR: the trait `core::ops::Index<u8>` is not implemented
+    [0][0u8]; //~ ERROR: the trait `std::ops::Index<u8>` is not implemented
 
     [0][0]; // should infer to be a usize
 
diff --git a/src/test/compile-fail/infinite-instantiation.rs b/src/test/compile-fail/infinite-instantiation.rs
index d293a1816d89e..08e6bf2469117 100644
--- a/src/test/compile-fail/infinite-instantiation.rs
+++ b/src/test/compile-fail/infinite-instantiation.rs
@@ -31,7 +31,7 @@ impl<T:Clone> ToOpt for Option<T> {
 }
 
 fn function<T:ToOpt + Clone>(counter: usize, t: T) {
-//~^ ERROR reached the recursion limit while instantiating `function::<core::option::Option<
+//~^ ERROR reached the recursion limit while instantiating `function::<std::option::Option<
     if counter > 0 {
         function(counter - 1, t.to_option());
         // FIXME(#4287) Error message should be here. It should be
diff --git a/src/test/compile-fail/integral-indexing.rs b/src/test/compile-fail/integral-indexing.rs
index f78d677679bc8..047ab9d2a8fdb 100644
--- a/src/test/compile-fail/integral-indexing.rs
+++ b/src/test/compile-fail/integral-indexing.rs
@@ -13,14 +13,14 @@ pub fn main() {
     let s: String = "abcdef".to_string();
     v[3_usize];
     v[3];
-    v[3u8];  //~ERROR the trait `core::ops::Index<u8>` is not implemented
-    v[3i8];  //~ERROR the trait `core::ops::Index<i8>` is not implemented
-    v[3u32]; //~ERROR the trait `core::ops::Index<u32>` is not implemented
-    v[3i32]; //~ERROR the trait `core::ops::Index<i32>` is not implemented
+    v[3u8];  //~ERROR the trait `std::ops::Index<u8>` is not implemented
+    v[3i8];  //~ERROR the trait `std::ops::Index<i8>` is not implemented
+    v[3u32]; //~ERROR the trait `std::ops::Index<u32>` is not implemented
+    v[3i32]; //~ERROR the trait `std::ops::Index<i32>` is not implemented
     s.as_bytes()[3_usize];
     s.as_bytes()[3];
-    s.as_bytes()[3u8];  //~ERROR the trait `core::ops::Index<u8>` is not implemented
-    s.as_bytes()[3i8];  //~ERROR the trait `core::ops::Index<i8>` is not implemented
-    s.as_bytes()[3u32]; //~ERROR the trait `core::ops::Index<u32>` is not implemented
-    s.as_bytes()[3i32]; //~ERROR the trait `core::ops::Index<i32>` is not implemented
+    s.as_bytes()[3u8];  //~ERROR the trait `std::ops::Index<u8>` is not implemented
+    s.as_bytes()[3i8];  //~ERROR the trait `std::ops::Index<i8>` is not implemented
+    s.as_bytes()[3u32]; //~ERROR the trait `std::ops::Index<u32>` is not implemented
+    s.as_bytes()[3i32]; //~ERROR the trait `std::ops::Index<i32>` is not implemented
 }
diff --git a/src/test/compile-fail/issue-13466.rs b/src/test/compile-fail/issue-13466.rs
index a29a83c430632..d2c8b679ff69f 100644
--- a/src/test/compile-fail/issue-13466.rs
+++ b/src/test/compile-fail/issue-13466.rs
@@ -17,16 +17,16 @@ pub fn main() {
     let _x: usize = match Some(1) {
         Ok(u) => u,
         //~^ ERROR mismatched types
-        //~| expected `core::option::Option<_>`
-        //~| found `core::result::Result<_, _>`
-        //~| expected enum `core::option::Option`
-        //~| found enum `core::result::Result`
+        //~| expected `std::option::Option<_>`
+        //~| found `std::result::Result<_, _>`
+        //~| expected enum `std::option::Option`
+        //~| found enum `std::result::Result`
 
         Err(e) => panic!(e)
         //~^ ERROR mismatched types
-        //~| expected `core::option::Option<_>`
-        //~| found `core::result::Result<_, _>`
-        //~| expected enum `core::option::Option`
-        //~| found enum `core::result::Result`
+        //~| expected `std::option::Option<_>`
+        //~| found `std::result::Result<_, _>`
+        //~| expected enum `std::option::Option`
+        //~| found enum `std::result::Result`
     };
 }
diff --git a/src/test/compile-fail/issue-14084.rs b/src/test/compile-fail/issue-14084.rs
index 8cbec549dda96..dfdbea5f76e03 100644
--- a/src/test/compile-fail/issue-14084.rs
+++ b/src/test/compile-fail/issue-14084.rs
@@ -13,5 +13,5 @@
 
 fn main() {
     () <- 0;
-    //~^ ERROR: the trait `core::ops::Placer<_>` is not implemented
+    //~^ ERROR: the trait `std::ops::Placer<_>` is not implemented
 }
diff --git a/src/test/compile-fail/issue-14366.rs b/src/test/compile-fail/issue-14366.rs
index c7cac71af0361..4019b265edde2 100644
--- a/src/test/compile-fail/issue-14366.rs
+++ b/src/test/compile-fail/issue-14366.rs
@@ -10,5 +10,5 @@
 
 fn main() {
     let _x = "test" as &::std::any::Any;
-//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `str`
+//~^ ERROR the trait `std::marker::Sized` is not implemented for the type `str`
 }
diff --git a/src/test/compile-fail/issue-15756.rs b/src/test/compile-fail/issue-15756.rs
index 02ccf9c0e08e7..eca6b02dbdc2e 100644
--- a/src/test/compile-fail/issue-15756.rs
+++ b/src/test/compile-fail/issue-15756.rs
@@ -15,7 +15,7 @@ fn dft_iter<'a, T>(arg1: Chunks<'a,T>, arg2: ChunksMut<'a,T>)
 {
     for
     &mut something
-//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `[T]`
+//~^ ERROR the trait `std::marker::Sized` is not implemented for the type `[T]`
     in arg2
     {
     }
diff --git a/src/test/compile-fail/issue-15783.rs b/src/test/compile-fail/issue-15783.rs
index 13a5fa4b8af5a..9a139021e4c6d 100644
--- a/src/test/compile-fail/issue-15783.rs
+++ b/src/test/compile-fail/issue-15783.rs
@@ -17,8 +17,8 @@ fn main() {
     let x = Some(&[name]);
     let msg = foo(x);
 //~^ ERROR mismatched types
-//~| expected `core::option::Option<&[&str]>`
-//~| found `core::option::Option<&[&str; 1]>`
+//~| expected `std::option::Option<&[&str]>`
+//~| found `std::option::Option<&[&str; 1]>`
 //~| expected slice
 //~| found array of 1 elements
     assert_eq!(msg, 3);
diff --git a/src/test/compile-fail/issue-16338.rs b/src/test/compile-fail/issue-16338.rs
index ba369734daa47..30775a958b57d 100644
--- a/src/test/compile-fail/issue-16338.rs
+++ b/src/test/compile-fail/issue-16338.rs
@@ -14,7 +14,7 @@ fn main() {
     let Slice { data: data, len: len } = "foo";
     //~^ ERROR mismatched types
     //~| expected `&str`
-    //~| found `core::raw::Slice<_>`
+    //~| found `std::raw::Slice<_>`
     //~| expected &-ptr
-    //~| found struct `core::raw::Slice`
+    //~| found struct `std::raw::Slice`
 }
diff --git a/src/test/compile-fail/issue-16401.rs b/src/test/compile-fail/issue-16401.rs
index b943ef510da28..a90f9fe26e48c 100644
--- a/src/test/compile-fail/issue-16401.rs
+++ b/src/test/compile-fail/issue-16401.rs
@@ -15,9 +15,9 @@ fn main() {
         Slice { data: data, len: len } => (),
         //~^ ERROR mismatched types
         //~| expected `()`
-        //~| found `core::raw::Slice<_>`
+        //~| found `std::raw::Slice<_>`
         //~| expected ()
-        //~| found struct `core::raw::Slice`
+        //~| found struct `std::raw::Slice`
         _ => unreachable!()
     }
 }
diff --git a/src/test/compile-fail/issue-16538.rs b/src/test/compile-fail/issue-16538.rs
index 205d3251cc2df..3b819916fbd55 100644
--- a/src/test/compile-fail/issue-16538.rs
+++ b/src/test/compile-fail/issue-16538.rs
@@ -19,7 +19,7 @@ mod Y {
 }
 
 static foo: *const Y::X = Y::foo(Y::x as *const Y::X);
-//~^ ERROR the trait `core::marker::Sync` is not implemented for the type
+//~^ ERROR the trait `std::marker::Sync` is not implemented for the type
 //~| ERROR cannot refer to other statics by value, use the address-of operator or a constant instead
 //~| ERROR E0015
 
diff --git a/src/test/compile-fail/issue-17441.rs b/src/test/compile-fail/issue-17441.rs
index 46a64f99354c6..7d300bfb14831 100644
--- a/src/test/compile-fail/issue-17441.rs
+++ b/src/test/compile-fail/issue-17441.rs
@@ -15,11 +15,11 @@ fn main() {
 
     // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
     let _bar = Box::new(1_usize) as std::fmt::Debug;
-    //~^ ERROR cast to unsized type: `Box<usize>` as `core::fmt::Debug`
+    //~^ ERROR cast to unsized type: `Box<usize>` as `std::fmt::Debug`
     //~^^ HELP try casting to a `Box` instead
 
     let _baz = 1_usize as std::fmt::Debug;
-    //~^ ERROR cast to unsized type: `usize` as `core::fmt::Debug`
+    //~^ ERROR cast to unsized type: `usize` as `std::fmt::Debug`
     //~^^ HELP consider using a box or reference as appropriate
 
     let _quux = [1_usize, 2] as [usize];
diff --git a/src/test/compile-fail/issue-17651.rs b/src/test/compile-fail/issue-17651.rs
index 9e49abc463f15..e079ef1ec12fa 100644
--- a/src/test/compile-fail/issue-17651.rs
+++ b/src/test/compile-fail/issue-17651.rs
@@ -14,5 +14,5 @@
 fn main() {
     // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
     (|| Box::new(*(&[0][..])))();
-    //~^ ERROR the trait `core::marker::Sized` is not implemented for the type `[_]`
+    //~^ ERROR the trait `std::marker::Sized` is not implemented for the type `[_]`
 }
diff --git a/src/test/compile-fail/issue-17718-static-sync.rs b/src/test/compile-fail/issue-17718-static-sync.rs
index fa8035a79652e..4b53d84f30554 100644
--- a/src/test/compile-fail/issue-17718-static-sync.rs
+++ b/src/test/compile-fail/issue-17718-static-sync.rs
@@ -17,6 +17,6 @@ impl !Sync for Foo {}
 
 static FOO: usize = 3;
 static BAR: Foo = Foo;
-//~^ ERROR: the trait `core::marker::Sync` is not implemented
+//~^ ERROR: the trait `std::marker::Sync` is not implemented
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-18107.rs b/src/test/compile-fail/issue-18107.rs
index 6300a1dc15d60..03a165f18dec7 100644
--- a/src/test/compile-fail/issue-18107.rs
+++ b/src/test/compile-fail/issue-18107.rs
@@ -12,7 +12,7 @@ pub trait AbstractRenderer {}
 
 fn _create_render(_: &()) ->
     AbstractRenderer
-//~^ ERROR: the trait `core::marker::Sized` is not implemented
+//~^ ERROR: the trait `std::marker::Sized` is not implemented
 {
     match 0 {
         _ => unimplemented!()
diff --git a/src/test/compile-fail/issue-18919.rs b/src/test/compile-fail/issue-18919.rs
index 8c2c52e6fad41..11083453d0518 100644
--- a/src/test/compile-fail/issue-18919.rs
+++ b/src/test/compile-fail/issue-18919.rs
@@ -11,7 +11,7 @@
 type FuncType<'f> = Fn(&isize) -> isize + 'f;
 
 fn ho_func(f: Option<FuncType>) {
-    //~^ ERROR: the trait `core::marker::Sized` is not implemented for the type
+    //~^ ERROR: the trait `std::marker::Sized` is not implemented for the type
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-20005.rs b/src/test/compile-fail/issue-20005.rs
index aaf27ba527b18..23b2532639bc8 100644
--- a/src/test/compile-fail/issue-20005.rs
+++ b/src/test/compile-fail/issue-20005.rs
@@ -15,7 +15,7 @@ trait From<Src> {
 }
 
 trait To {
-    fn to<Dst>(  //~ ERROR the trait `core::marker::Sized` is not implemented
+    fn to<Dst>(  //~ ERROR the trait `std::marker::Sized` is not implemented
         self
     ) -> <Dst as From<Self>>::Result where Dst: From<Self> {
         From::from(self)
diff --git a/src/test/compile-fail/issue-20162.rs b/src/test/compile-fail/issue-20162.rs
index d3a87689ac5e1..c81bcb828248f 100644
--- a/src/test/compile-fail/issue-20162.rs
+++ b/src/test/compile-fail/issue-20162.rs
@@ -13,5 +13,5 @@ struct X { x: i32 }
 fn main() {
     let mut b: Vec<X> = vec![];
     b.sort();
-    //~^ ERROR the trait `core::cmp::Ord` is not implemented for the type `X`
+    //~^ ERROR the trait `std::cmp::Ord` is not implemented for the type `X`
 }
diff --git a/src/test/compile-fail/issue-20605.rs b/src/test/compile-fail/issue-20605.rs
index f2d65af9cdfc8..c0eea477775b6 100644
--- a/src/test/compile-fail/issue-20605.rs
+++ b/src/test/compile-fail/issue-20605.rs
@@ -10,7 +10,7 @@
 
 fn changer<'a>(mut things: Box<Iterator<Item=&'a mut u8>>) {
     for item in *things { *item = 0 }
-//~^ ERROR the trait `core::marker::Sized` is not implemented for the type `core::iter::Iterator
+//~^ ERROR the trait `std::marker::Sized` is not implemented for the type `std::iter::Iterator
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-21160.rs b/src/test/compile-fail/issue-21160.rs
index 557bf518a3cfb..f25f872167536 100644
--- a/src/test/compile-fail/issue-21160.rs
+++ b/src/test/compile-fail/issue-21160.rs
@@ -16,6 +16,6 @@ impl Bar {
 
 #[derive(Hash)]
 struct Foo(Bar);
-//~^ error: the trait `core::hash::Hash` is not implemented for the type `Bar`
+//~^ error: the trait `std::hash::Hash` is not implemented for the type `Bar`
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-21332.rs b/src/test/compile-fail/issue-21332.rs
index f25a9fd276252..b36918149fa99 100644
--- a/src/test/compile-fail/issue-21332.rs
+++ b/src/test/compile-fail/issue-21332.rs
@@ -14,8 +14,8 @@ impl Iterator for S {
     type Item = i32;
     fn next(&mut self) -> Result<i32, i32> { Ok(7) }
     //~^ ERROR method `next` has an incompatible type for trait
-    //~| expected enum `core::option::Option`
-    //~|    found enum `core::result::Result` [E0053]
+    //~| expected enum `std::option::Option`
+    //~|    found enum `std::result::Result` [E0053]
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-21763.rs b/src/test/compile-fail/issue-21763.rs
index bcf3a0a9ac62b..e535567c52e3b 100644
--- a/src/test/compile-fail/issue-21763.rs
+++ b/src/test/compile-fail/issue-21763.rs
@@ -17,5 +17,5 @@ fn foo<T: Send>() {}
 
 fn main() {
     foo::<HashMap<Rc<()>, Rc<()>>>();
-    //~^ ERROR: the trait `core::marker::Send` is not implemented for the type `alloc::rc::Rc<()>`
+    //~^ ERROR: the trait `std::marker::Send` is not implemented for the type `std::rc::Rc<()>`
 }
diff --git a/src/test/compile-fail/issue-21950.rs b/src/test/compile-fail/issue-21950.rs
index ef6ce5c995bf3..1028923ec82fd 100644
--- a/src/test/compile-fail/issue-21950.rs
+++ b/src/test/compile-fail/issue-21950.rs
@@ -16,5 +16,5 @@ fn main() {
     let x = &10 as
             &Add;
             //~^ ERROR the type parameter `RHS` must be explicitly specified in an object type because its default value `Self` references the type `Self`
-            //~| ERROR the value of the associated type `Output` (from the trait `core::ops::Add`) must be specified
+            //~| ERROR the value of the associated type `Output` (from the trait `std::ops::Add`) must be specified
 }
diff --git a/src/test/compile-fail/issue-22034.rs b/src/test/compile-fail/issue-22034.rs
index 8b258180e830f..a72839347105a 100644
--- a/src/test/compile-fail/issue-22034.rs
+++ b/src/test/compile-fail/issue-22034.rs
@@ -14,7 +14,7 @@ fn main() {
     let ptr: *mut () = 0 as *mut _;
     let _: &mut Fn() = unsafe {
         &mut *(ptr as *mut Fn())
-        //~^ ERROR the trait `core::ops::Fn<()>` is not implemented
-        //~| ERROR the trait `core::ops::FnOnce<()>` is not implemented
+        //~^ ERROR the trait `std::ops::Fn<()>` is not implemented
+        //~| ERROR the trait `std::ops::FnOnce<()>` is not implemented
     };
 }
diff --git a/src/test/compile-fail/issue-22560.rs b/src/test/compile-fail/issue-22560.rs
index a05bbe4960e7c..20ec2d64ae6a8 100644
--- a/src/test/compile-fail/issue-22560.rs
+++ b/src/test/compile-fail/issue-22560.rs
@@ -14,7 +14,7 @@ use std::ops::{Add, Sub};
 
 type Test = Add +
             //~^ ERROR the type parameter `RHS` must be explicitly specified in an object type because its default value `Self` references the type `Self`
-            //~^^ ERROR the value of the associated type `Output` (from the trait `core::ops::Add`) must be specified [E0191]
+            //~^^ ERROR the value of the associated type `Output` (from the trait `std::ops::Add`) must be specified [E0191]
             Sub;
             //~^ ERROR only the builtin traits can be used as closure or object bounds
 
diff --git a/src/test/compile-fail/issue-23024.rs b/src/test/compile-fail/issue-23024.rs
index 92610c1c6d33c..df2a70160f866 100644
--- a/src/test/compile-fail/issue-23024.rs
+++ b/src/test/compile-fail/issue-23024.rs
@@ -19,5 +19,5 @@ fn main()
     println!("{:?}",(vfnfer[0] as Fn)(3));
     //~^ ERROR the precise format of `Fn`-family traits'
     //~| ERROR wrong number of type arguments: expected 1, found 0
-    //~| ERROR the value of the associated type `Output` (from the trait `core::ops::FnOnce`)
+    //~| ERROR the value of the associated type `Output` (from the trait `std::ops::FnOnce`)
 }
diff --git a/src/test/compile-fail/issue-24446.rs b/src/test/compile-fail/issue-24446.rs
index 1fca8eb6ac4f3..cafe6d1bb5829 100644
--- a/src/test/compile-fail/issue-24446.rs
+++ b/src/test/compile-fail/issue-24446.rs
@@ -11,9 +11,9 @@
 fn main() {
     static foo: Fn() -> u32 = || -> u32 {
         //~^ ERROR: mismatched types:
-        //~| expected `core::ops::Fn() -> u32 + 'static`,
+        //~| expected `std::ops::Fn() -> u32 + 'static`,
         //~| found closure
-        //~| (expected trait core::ops::Fn,
+        //~| (expected trait std::ops::Fn,
         //~| found closure)
         0
     };
diff --git a/src/test/compile-fail/issue-2611-4.rs b/src/test/compile-fail/issue-2611-4.rs
index 24cc0099b89a5..49f024399c7e7 100644
--- a/src/test/compile-fail/issue-2611-4.rs
+++ b/src/test/compile-fail/issue-2611-4.rs
@@ -21,7 +21,7 @@ struct E {
 
 impl A for E {
     fn b<F: Sync, G>(&self, _x: F) -> F { panic!() }
-    //~^ ERROR `F : core::marker::Sync` appears on the impl method
+    //~^ ERROR `F : std::marker::Sync` appears on the impl method
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-28098.rs b/src/test/compile-fail/issue-28098.rs
index f565d24e1fd08..d81abd417f11f 100644
--- a/src/test/compile-fail/issue-28098.rs
+++ b/src/test/compile-fail/issue-28098.rs
@@ -10,13 +10,13 @@
 
 fn main() {
     let _ = Iterator::next(&mut ());
-    //~^ ERROR the trait `core::iter::Iterator` is not implemented
+    //~^ ERROR the trait `std::iter::Iterator` is not implemented
 
     for _ in false {}
-    //~^ ERROR the trait `core::iter::Iterator` is not implemented
+    //~^ ERROR the trait `std::iter::Iterator` is not implemented
 
     let _ = Iterator::next(&mut ());
-    //~^ ERROR the trait `core::iter::Iterator` is not implemented
+    //~^ ERROR the trait `std::iter::Iterator` is not implemented
 
     other()
 }
@@ -25,11 +25,11 @@ pub fn other() {
     // check errors are still reported globally
 
     let _ = Iterator::next(&mut ());
-    //~^ ERROR the trait `core::iter::Iterator` is not implemented
+    //~^ ERROR the trait `std::iter::Iterator` is not implemented
 
     let _ = Iterator::next(&mut ());
-    //~^ ERROR the trait `core::iter::Iterator` is not implemented
+    //~^ ERROR the trait `std::iter::Iterator` is not implemented
 
     for _ in false {}
-    //~^ ERROR the trait `core::iter::Iterator` is not implemented
+    //~^ ERROR the trait `std::iter::Iterator` is not implemented
 }
diff --git a/src/test/compile-fail/issue-3680.rs b/src/test/compile-fail/issue-3680.rs
index 4aff95b57decb..fc918c278ef5d 100644
--- a/src/test/compile-fail/issue-3680.rs
+++ b/src/test/compile-fail/issue-3680.rs
@@ -12,9 +12,9 @@ fn main() {
     match None {
         Err(_) => ()
         //~^ ERROR mismatched types
-        //~| expected `core::option::Option<_>`
-        //~| found `core::result::Result<_, _>`
-        //~| expected enum `core::option::Option`
-        //~| found enum `core::result::Result`
+        //~| expected `std::option::Option<_>`
+        //~| found `std::result::Result<_, _>`
+        //~| expected enum `std::option::Option`
+        //~| found enum `std::result::Result`
     }
 }
diff --git a/src/test/compile-fail/issue-5035-2.rs b/src/test/compile-fail/issue-5035-2.rs
index 9e324cdd61eb0..a96eb0e721bd9 100644
--- a/src/test/compile-fail/issue-5035-2.rs
+++ b/src/test/compile-fail/issue-5035-2.rs
@@ -11,6 +11,6 @@
 trait I {}
 type K = I+'static;
 
-fn foo(_x: K) {} //~ ERROR: the trait `core::marker::Sized` is not implemented
+fn foo(_x: K) {} //~ ERROR: the trait `std::marker::Sized` is not implemented
 
 fn main() {}
diff --git a/src/test/compile-fail/issue-5883.rs b/src/test/compile-fail/issue-5883.rs
index 9ff957b6e6dea..cc6c797c76619 100644
--- a/src/test/compile-fail/issue-5883.rs
+++ b/src/test/compile-fail/issue-5883.rs
@@ -15,8 +15,8 @@ struct Struct {
 }
 
 fn new_struct(r: A+'static)
-    -> Struct { //~^  ERROR the trait `core::marker::Sized` is not implemented
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    -> Struct { //~^  ERROR the trait `std::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
     Struct { r: r }
 }
 
diff --git a/src/test/compile-fail/issue-7013.rs b/src/test/compile-fail/issue-7013.rs
index 90ecfb6015dcd..1293bf22b47de 100644
--- a/src/test/compile-fail/issue-7013.rs
+++ b/src/test/compile-fail/issue-7013.rs
@@ -34,5 +34,5 @@ struct A {
 
 fn main() {
     let a = A {v: box B{v: None} as Box<Foo+Send>};
-    //~^ ERROR the trait `core::marker::Send` is not implemented
+    //~^ ERROR the trait `std::marker::Send` is not implemented
 }
diff --git a/src/test/compile-fail/issue-7092.rs b/src/test/compile-fail/issue-7092.rs
index eefb34fbe4c91..4a278bbdeb04a 100644
--- a/src/test/compile-fail/issue-7092.rs
+++ b/src/test/compile-fail/issue-7092.rs
@@ -16,9 +16,9 @@ fn foo(x: Whatever) {
         Some(field) =>
 //~^ ERROR mismatched types
 //~| expected `Whatever`
-//~| found `core::option::Option<_>`
+//~| found `std::option::Option<_>`
 //~| expected enum `Whatever`
-//~| found enum `core::option::Option`
+//~| found enum `std::option::Option`
             field.access(), //~ ERROR the type of this value must be known in this context
     }
 }
diff --git a/src/test/compile-fail/issue-7364.rs b/src/test/compile-fail/issue-7364.rs
index 87b7b73d57dbd..726f789983d3c 100644
--- a/src/test/compile-fail/issue-7364.rs
+++ b/src/test/compile-fail/issue-7364.rs
@@ -16,6 +16,6 @@ use std::cell::RefCell;
 // Regression test for issue 7364
 static boxed: Box<RefCell<isize>> = box RefCell::new(0);
 //~^ ERROR allocations are not allowed in statics
-//~| ERROR the trait `core::marker::Sync` is not implemented for the type
+//~| ERROR the trait `std::marker::Sync` is not implemented for the type
 
 fn main() { }
diff --git a/src/test/compile-fail/issue-7867.rs b/src/test/compile-fail/issue-7867.rs
index 400806c3a5fa6..95513860b084f 100644
--- a/src/test/compile-fail/issue-7867.rs
+++ b/src/test/compile-fail/issue-7867.rs
@@ -26,15 +26,15 @@ fn main() {
     match &Some(42) {
         Some(x) => (),
         //~^ ERROR mismatched types
-        //~| expected `&core::option::Option<_>`
-        //~| found `core::option::Option<_>`
+        //~| expected `&std::option::Option<_>`
+        //~| found `std::option::Option<_>`
         //~| expected &-ptr
-        //~| found enum `core::option::Option`
+        //~| found enum `std::option::Option`
         None => ()
         //~^ ERROR mismatched types
-        //~| expected `&core::option::Option<_>`
-        //~| found `core::option::Option<_>`
+        //~| expected `&std::option::Option<_>`
+        //~| found `std::option::Option<_>`
         //~| expected &-ptr
-        //~| found enum `core::option::Option`
+        //~| found enum `std::option::Option`
     }
 }
diff --git a/src/test/compile-fail/issue-8727.rs b/src/test/compile-fail/issue-8727.rs
index 525ec85576284..18b7948c46c7c 100644
--- a/src/test/compile-fail/issue-8727.rs
+++ b/src/test/compile-fail/issue-8727.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:reached the recursion limit while instantiating `generic::<core::option::Option<
+// error-pattern:reached the recursion limit while instantiating `generic::<std::option::Option<
 
 // Verify the compiler fails with an error on infinite function
 // recursions.
diff --git a/src/test/compile-fail/kindck-copy.rs b/src/test/compile-fail/kindck-copy.rs
index 997c940c9547e..4bc941628aad9 100644
--- a/src/test/compile-fail/kindck-copy.rs
+++ b/src/test/compile-fail/kindck-copy.rs
@@ -34,14 +34,14 @@ fn test<'a,T,U:Copy>(_: &'a isize) {
     assert_copy::<&'a [isize]>();
 
     // ...unless they are mutable
-    assert_copy::<&'static mut isize>(); //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<&'a mut isize>();  //~ ERROR `core::marker::Copy` is not implemented
+    assert_copy::<&'static mut isize>(); //~ ERROR `std::marker::Copy` is not implemented
+    assert_copy::<&'a mut isize>();  //~ ERROR `std::marker::Copy` is not implemented
 
     // boxes are not ok
-    assert_copy::<Box<isize>>();   //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<String>();   //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<Vec<isize> >(); //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<Box<&'a mut isize>>(); //~ ERROR `core::marker::Copy` is not implemented
+    assert_copy::<Box<isize>>();   //~ ERROR `std::marker::Copy` is not implemented
+    assert_copy::<String>();   //~ ERROR `std::marker::Copy` is not implemented
+    assert_copy::<Vec<isize> >(); //~ ERROR `std::marker::Copy` is not implemented
+    assert_copy::<Box<&'a mut isize>>(); //~ ERROR `std::marker::Copy` is not implemented
 
     // borrowed object types are generally ok
     assert_copy::<&'a Dummy>();
@@ -49,11 +49,11 @@ fn test<'a,T,U:Copy>(_: &'a isize) {
     assert_copy::<&'static (Dummy+Copy)>();
 
     // owned object types are not ok
-    assert_copy::<Box<Dummy>>(); //~ ERROR `core::marker::Copy` is not implemented
-    assert_copy::<Box<Dummy+Copy>>(); //~ ERROR `core::marker::Copy` is not implemented
+    assert_copy::<Box<Dummy>>(); //~ ERROR `std::marker::Copy` is not implemented
+    assert_copy::<Box<Dummy+Copy>>(); //~ ERROR `std::marker::Copy` is not implemented
 
     // mutable object types are not ok
-    assert_copy::<&'a mut (Dummy+Copy)>();  //~ ERROR `core::marker::Copy` is not implemented
+    assert_copy::<&'a mut (Dummy+Copy)>();  //~ ERROR `std::marker::Copy` is not implemented
 
     // unsafe ptrs are ok
     assert_copy::<*const isize>();
@@ -71,10 +71,10 @@ fn test<'a,T,U:Copy>(_: &'a isize) {
     assert_copy::<MyStruct>();
 
     // structs containing non-POD are not ok
-    assert_copy::<MyNoncopyStruct>(); //~ ERROR `core::marker::Copy` is not implemented
+    assert_copy::<MyNoncopyStruct>(); //~ ERROR `std::marker::Copy` is not implemented
 
     // ref counted types are not ok
-    assert_copy::<Rc<isize>>();   //~ ERROR `core::marker::Copy` is not implemented
+    assert_copy::<Rc<isize>>();   //~ ERROR `std::marker::Copy` is not implemented
 }
 
 pub fn main() {
diff --git a/src/test/compile-fail/kindck-impl-type-params-2.rs b/src/test/compile-fail/kindck-impl-type-params-2.rs
index 66297d70ef505..c5c50789e4005 100644
--- a/src/test/compile-fail/kindck-impl-type-params-2.rs
+++ b/src/test/compile-fail/kindck-impl-type-params-2.rs
@@ -21,5 +21,5 @@ fn take_param<T:Foo>(foo: &T) { }
 fn main() {
     let x: Box<_> = box 3;
     take_param(&x);
-    //~^ ERROR the trait `core::marker::Copy` is not implemented
+    //~^ ERROR the trait `std::marker::Copy` is not implemented
 }
diff --git a/src/test/compile-fail/kindck-impl-type-params.rs b/src/test/compile-fail/kindck-impl-type-params.rs
index aec40c1a73a80..a59c243f12a54 100644
--- a/src/test/compile-fail/kindck-impl-type-params.rs
+++ b/src/test/compile-fail/kindck-impl-type-params.rs
@@ -26,13 +26,13 @@ impl<T: Send + Copy + 'static> Gettable<T> for S<T> {}
 fn f<T>(val: T) {
     let t: S<T> = S(marker::PhantomData);
     let a = &t as &Gettable<T>;
-    //~^ ERROR the trait `core::marker::Send` is not implemented
+    //~^ ERROR the trait `std::marker::Send` is not implemented
 }
 
 fn g<T>(val: T) {
     let t: S<T> = S(marker::PhantomData);
     let a: &Gettable<T> = &t;
-    //~^ ERROR the trait `core::marker::Send` is not implemented
+    //~^ ERROR the trait `std::marker::Send` is not implemented
 }
 
 fn foo<'a>() {
@@ -44,7 +44,7 @@ fn foo<'a>() {
 fn foo2<'a>() {
     let t: Box<S<String>> = box S(marker::PhantomData);
     let a = t as Box<Gettable<String>>;
-    //~^ ERROR the trait `core::marker::Copy` is not implemented
+    //~^ ERROR the trait `std::marker::Copy` is not implemented
 }
 
 fn foo3<'a>() {
@@ -52,7 +52,7 @@ fn foo3<'a>() {
 
     let t: Box<S<Foo>> = box S(marker::PhantomData);
     let a: Box<Gettable<Foo>> = t;
-    //~^ ERROR the trait `core::marker::Copy` is not implemented
+    //~^ ERROR the trait `std::marker::Copy` is not implemented
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/kindck-nonsendable-1.rs b/src/test/compile-fail/kindck-nonsendable-1.rs
index bf2a209c4c48e..a207b8721224b 100644
--- a/src/test/compile-fail/kindck-nonsendable-1.rs
+++ b/src/test/compile-fail/kindck-nonsendable-1.rs
@@ -18,5 +18,5 @@ fn bar<F:FnOnce() + Send>(_: F) { }
 fn main() {
     let x = Rc::new(3);
     bar(move|| foo(x));
-    //~^ ERROR `core::marker::Send` is not implemented
+    //~^ ERROR `std::marker::Send` is not implemented
 }
diff --git a/src/test/compile-fail/kindck-send-object.rs b/src/test/compile-fail/kindck-send-object.rs
index 570f7ad7fe3bf..7525ff932bbd9 100644
--- a/src/test/compile-fail/kindck-send-object.rs
+++ b/src/test/compile-fail/kindck-send-object.rs
@@ -20,11 +20,11 @@ trait Message : Send { }
 
 fn object_ref_with_static_bound_not_ok() {
     assert_send::<&'static (Dummy+'static)>();
-    //~^ ERROR the trait `core::marker::Sync` is not implemented
+    //~^ ERROR the trait `std::marker::Sync` is not implemented
 }
 
 fn box_object_with_no_bound_not_ok<'a>() {
-    assert_send::<Box<Dummy>>(); //~ ERROR the trait `core::marker::Send` is not implemented
+    assert_send::<Box<Dummy>>(); //~ ERROR the trait `std::marker::Send` is not implemented
 }
 
 fn object_with_send_bound_ok() {
diff --git a/src/test/compile-fail/kindck-send-object1.rs b/src/test/compile-fail/kindck-send-object1.rs
index 48d5215b7085b..0e737e1b16279 100644
--- a/src/test/compile-fail/kindck-send-object1.rs
+++ b/src/test/compile-fail/kindck-send-object1.rs
@@ -18,7 +18,7 @@ trait Dummy { }
 // careful with object types, who knows what they close over...
 fn test51<'a>() {
     assert_send::<&'a Dummy>();
-    //~^ ERROR the trait `core::marker::Sync` is not implemented
+    //~^ ERROR the trait `std::marker::Sync` is not implemented
 }
 fn test52<'a>() {
     assert_send::<&'a (Dummy+Sync)>();
@@ -37,7 +37,7 @@ fn test61() {
 // them not ok
 fn test_71<'a>() {
     assert_send::<Box<Dummy+'a>>();
-    //~^ ERROR the trait `core::marker::Send` is not implemented
+    //~^ ERROR the trait `std::marker::Send` is not implemented
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/kindck-send-object2.rs b/src/test/compile-fail/kindck-send-object2.rs
index d3d166e2a6916..7bc86df57394e 100644
--- a/src/test/compile-fail/kindck-send-object2.rs
+++ b/src/test/compile-fail/kindck-send-object2.rs
@@ -14,11 +14,11 @@ fn assert_send<T:Send>() { }
 trait Dummy { }
 
 fn test50() {
-    assert_send::<&'static Dummy>(); //~ ERROR the trait `core::marker::Sync` is not implemented
+    assert_send::<&'static Dummy>(); //~ ERROR the trait `std::marker::Sync` is not implemented
 }
 
 fn test53() {
-    assert_send::<Box<Dummy>>(); //~ ERROR the trait `core::marker::Send` is not implemented
+    assert_send::<Box<Dummy>>(); //~ ERROR the trait `std::marker::Send` is not implemented
 }
 
 // ...unless they are properly bounded
diff --git a/src/test/compile-fail/kindck-send-owned.rs b/src/test/compile-fail/kindck-send-owned.rs
index 406711902a543..d7116930fb479 100644
--- a/src/test/compile-fail/kindck-send-owned.rs
+++ b/src/test/compile-fail/kindck-send-owned.rs
@@ -19,7 +19,7 @@ fn test32() { assert_send::<Vec<isize> >(); }
 
 // but not if they own a bad thing
 fn test40() {
-    assert_send::<Box<*mut u8>>(); //~ ERROR `core::marker::Send` is not implemented
+    assert_send::<Box<*mut u8>>(); //~ ERROR `std::marker::Send` is not implemented
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/method-help-unsatisfied-bound.rs b/src/test/compile-fail/method-help-unsatisfied-bound.rs
index 375d5076ea2f8..6416d5467c890 100644
--- a/src/test/compile-fail/method-help-unsatisfied-bound.rs
+++ b/src/test/compile-fail/method-help-unsatisfied-bound.rs
@@ -13,6 +13,6 @@ struct Foo;
 fn main() {
     let a: Result<(), Foo> = Ok(());
     a.unwrap();
-    //~^ ERROR no method named `unwrap` found for type `core::result::Result<(), Foo>`
-    //~| NOTE the following trait bounds were not satisfied: `Foo : core::fmt::Debug`
+    //~^ ERROR no method named `unwrap` found for type `std::result::Result<(), Foo>`
+    //~| NOTE the following trait bounds were not satisfied: `Foo : std::fmt::Debug`
 }
diff --git a/src/test/compile-fail/minus-string.rs b/src/test/compile-fail/minus-string.rs
index 9a89424c61f34..1ba30c67a03cf 100644
--- a/src/test/compile-fail/minus-string.rs
+++ b/src/test/compile-fail/minus-string.rs
@@ -8,6 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:cannot apply unary operator `-` to type `collections::string::String`
+// error-pattern:cannot apply unary operator `-` to type `std::string::String`
 
 fn main() { -"foo".to_string(); }
diff --git a/src/test/compile-fail/mut-not-freeze.rs b/src/test/compile-fail/mut-not-freeze.rs
index db19132b2c454..a12a3615bc91a 100644
--- a/src/test/compile-fail/mut-not-freeze.rs
+++ b/src/test/compile-fail/mut-not-freeze.rs
@@ -15,5 +15,5 @@ fn f<T: Sync>(_: T) {}
 fn main() {
     let x = RefCell::new(0);
     f(x);
-    //~^ ERROR `core::marker::Sync` is not implemented
+    //~^ ERROR `std::marker::Sync` is not implemented
 }
diff --git a/src/test/compile-fail/mutable-enum-indirect.rs b/src/test/compile-fail/mutable-enum-indirect.rs
index 1657d602e24c4..a7e751e7ea95b 100644
--- a/src/test/compile-fail/mutable-enum-indirect.rs
+++ b/src/test/compile-fail/mutable-enum-indirect.rs
@@ -24,5 +24,5 @@ fn bar<T: Sync>(_: T) {}
 
 fn main() {
     let x = Foo::A(NoSync);
-    bar(&x); //~ ERROR the trait `core::marker::Sync` is not implemented
+    bar(&x); //~ ERROR the trait `std::marker::Sync` is not implemented
 }
diff --git a/src/test/compile-fail/no-method-suggested-traits.rs b/src/test/compile-fail/no-method-suggested-traits.rs
index 1683db811cf04..9ccc7cc75ad5a 100644
--- a/src/test/compile-fail/no-method-suggested-traits.rs
+++ b/src/test/compile-fail/no-method-suggested-traits.rs
@@ -65,7 +65,7 @@ fn main() {
     //~^^ HELP following traits define an item `method`, perhaps you need to implement one of them
     //~^^^ HELP `foo::Bar`
     //~^^^^ HELP `no_method_suggested_traits::foo::PubPub`
-    //~^^^^^ HELP `no_method_suggested_traits::reexport::Reexported`
+    //~^^^^^ HELP `no_method_suggested_traits::Reexported`
     //~^^^^^^ HELP `no_method_suggested_traits::bar::PubPriv`
     //~^^^^^^^ HELP `no_method_suggested_traits::qux::PrivPub`
     //~^^^^^^^^ HELP `no_method_suggested_traits::quz::PrivPriv`
@@ -74,7 +74,7 @@ fn main() {
     //~^^ HELP following traits define an item `method`, perhaps you need to implement one of them
     //~^^^ HELP `foo::Bar`
     //~^^^^ HELP `no_method_suggested_traits::foo::PubPub`
-    //~^^^^^ HELP `no_method_suggested_traits::reexport::Reexported`
+    //~^^^^^ HELP `no_method_suggested_traits::Reexported`
     //~^^^^^^ HELP `no_method_suggested_traits::bar::PubPriv`
     //~^^^^^^^ HELP `no_method_suggested_traits::qux::PrivPub`
     //~^^^^^^^^ HELP `no_method_suggested_traits::quz::PrivPriv`
diff --git a/src/test/compile-fail/no-send-res-ports.rs b/src/test/compile-fail/no-send-res-ports.rs
index 60b2d22079e2c..2bb0343400c27 100644
--- a/src/test/compile-fail/no-send-res-ports.rs
+++ b/src/test/compile-fail/no-send-res-ports.rs
@@ -33,7 +33,7 @@ fn main() {
     let x = foo(Port(Rc::new(())));
 
     thread::spawn(move|| {
-        //~^ ERROR `core::marker::Send` is not implemented
+        //~^ ERROR `std::marker::Send` is not implemented
         let y = x;
         println!("{:?}", y);
     });
diff --git a/src/test/compile-fail/no_send-enum.rs b/src/test/compile-fail/no_send-enum.rs
index 625d51260c4dc..7505bf69c8310 100644
--- a/src/test/compile-fail/no_send-enum.rs
+++ b/src/test/compile-fail/no_send-enum.rs
@@ -24,5 +24,5 @@ fn bar<T: Send>(_: T) {}
 fn main() {
     let x = Foo::A(NoSend);
     bar(x);
-    //~^ ERROR `core::marker::Send` is not implemented
+    //~^ ERROR `std::marker::Send` is not implemented
 }
diff --git a/src/test/compile-fail/no_send-rc.rs b/src/test/compile-fail/no_send-rc.rs
index b5c572b17dd9a..23926394a2358 100644
--- a/src/test/compile-fail/no_send-rc.rs
+++ b/src/test/compile-fail/no_send-rc.rs
@@ -15,5 +15,5 @@ fn bar<T: Send>(_: T) {}
 fn main() {
     let x = Rc::new(5);
     bar(x);
-    //~^ ERROR `core::marker::Send` is not implemented
+    //~^ ERROR `std::marker::Send` is not implemented
 }
diff --git a/src/test/compile-fail/no_send-struct.rs b/src/test/compile-fail/no_send-struct.rs
index 7f16db0ba947b..14e18558a717c 100644
--- a/src/test/compile-fail/no_send-struct.rs
+++ b/src/test/compile-fail/no_send-struct.rs
@@ -23,5 +23,5 @@ fn bar<T: Send>(_: T) {}
 fn main() {
     let x = Foo { a: 5 };
     bar(x);
-    //~^ ERROR the trait `core::marker::Send` is not implemented
+    //~^ ERROR the trait `std::marker::Send` is not implemented
 }
diff --git a/src/test/compile-fail/no_share-enum.rs b/src/test/compile-fail/no_share-enum.rs
index 9331afdbbb5d7..c9a3084a73e62 100644
--- a/src/test/compile-fail/no_share-enum.rs
+++ b/src/test/compile-fail/no_share-enum.rs
@@ -22,5 +22,5 @@ fn bar<T: Sync>(_: T) {}
 fn main() {
     let x = Foo::A(NoSync);
     bar(x);
-    //~^ ERROR the trait `core::marker::Sync` is not implemented
+    //~^ ERROR the trait `std::marker::Sync` is not implemented
 }
diff --git a/src/test/compile-fail/no_share-struct.rs b/src/test/compile-fail/no_share-struct.rs
index b5ccceb3b2a7d..74549286f7b57 100644
--- a/src/test/compile-fail/no_share-struct.rs
+++ b/src/test/compile-fail/no_share-struct.rs
@@ -20,5 +20,5 @@ fn bar<T: Sync>(_: T) {}
 fn main() {
     let x = Foo { a: 5 };
     bar(x);
-    //~^ ERROR the trait `core::marker::Sync` is not implemented
+    //~^ ERROR the trait `std::marker::Sync` is not implemented
 }
diff --git a/src/test/compile-fail/noexporttypeexe.rs b/src/test/compile-fail/noexporttypeexe.rs
index 85a47492306af..687e1e49ee844 100644
--- a/src/test/compile-fail/noexporttypeexe.rs
+++ b/src/test/compile-fail/noexporttypeexe.rs
@@ -20,7 +20,7 @@ fn main() {
   let x: isize = noexporttypelib::foo();
     //~^ ERROR mismatched types
     //~| expected `isize`
-    //~| found `core::option::Option<isize>`
+    //~| found `std::option::Option<isize>`
     //~| expected isize
-    //~| found enum `core::option::Option`
+    //~| found enum `std::option::Option`
 }
diff --git a/src/test/compile-fail/not-sync.rs b/src/test/compile-fail/not-sync.rs
index a60138c6e1f69..c9648a18be5f2 100644
--- a/src/test/compile-fail/not-sync.rs
+++ b/src/test/compile-fail/not-sync.rs
@@ -16,14 +16,14 @@ fn test<T: Sync>() {}
 
 fn main() {
     test::<Cell<i32>>();
-    //~^ ERROR marker::Sync` is not implemented for the type `core::cell::Cell<i32>`
+    //~^ ERROR marker::Sync` is not implemented for the type `std::cell::Cell<i32>`
     test::<RefCell<i32>>();
-    //~^ ERROR marker::Sync` is not implemented for the type `core::cell::RefCell<i32>`
+    //~^ ERROR marker::Sync` is not implemented for the type `std::cell::RefCell<i32>`
 
     test::<Rc<i32>>();
-    //~^ ERROR marker::Sync` is not implemented for the type `alloc::rc::Rc<i32>`
+    //~^ ERROR marker::Sync` is not implemented for the type `std::rc::Rc<i32>`
     test::<Weak<i32>>();
-    //~^ ERROR marker::Sync` is not implemented for the type `alloc::rc::Weak<i32>`
+    //~^ ERROR marker::Sync` is not implemented for the type `std::rc::Weak<i32>`
 
     test::<Receiver<i32>>();
     //~^ ERROR marker::Sync` is not implemented for the type `std::sync::mpsc::Receiver<i32>`
diff --git a/src/test/compile-fail/on-unimplemented.rs b/src/test/compile-fail/on-unimplemented.rs
index f386e7cdd5a96..39ce1b33ca131 100644
--- a/src/test/compile-fail/on-unimplemented.rs
+++ b/src/test/compile-fail/on-unimplemented.rs
@@ -33,9 +33,9 @@ pub fn main() {
     let x = vec!(1u8, 2, 3, 4);
     let y: Option<Vec<u8>> = collect(x.iter()); // this should give approximately the same error for x.iter().collect()
     //~^ ERROR
-    //~^^ NOTE a collection of type `core::option::Option<collections::vec::Vec<u8>>` cannot be built from an iterator over elements of type `&u8`
+    //~^^ NOTE a collection of type `std::option::Option<std::vec::Vec<u8>>` cannot be built from an iterator over elements of type `&u8`
     //~^^^ NOTE required by `collect`
     let x: String = foobar(); //~ ERROR
-    //~^ NOTE test error `collections::string::String` with `u8` `_` `u32`
+    //~^ NOTE test error `std::string::String` with `u8` `_` `u32`
     //~^^ NOTE required by `foobar`
 }
diff --git a/src/test/compile-fail/phantom-oibit.rs b/src/test/compile-fail/phantom-oibit.rs
index 071b4db40f86f..92def18f82414 100644
--- a/src/test/compile-fail/phantom-oibit.rs
+++ b/src/test/compile-fail/phantom-oibit.rs
@@ -31,11 +31,11 @@ struct Nested<T>(T);
 fn is_zen<T: Zen>(_: T) {}
 
 fn not_sync<T>(x: Guard<T>) {
-    is_zen(x)  //~ error: the trait `core::marker::Sync` is not implemented for the type `T`
+    is_zen(x)  //~ error: the trait `std::marker::Sync` is not implemented for the type `T`
 }
 
 fn nested_not_sync<T>(x: Nested<Guard<T>>) {
-    is_zen(x)  //~ error: the trait `core::marker::Sync` is not implemented for the type `T`
+    is_zen(x)  //~ error: the trait `std::marker::Sync` is not implemented for the type `T`
 }
 
 fn main() {}
diff --git a/src/test/compile-fail/range-1.rs b/src/test/compile-fail/range-1.rs
index e4ab5829f4168..46d7666dabc56 100644
--- a/src/test/compile-fail/range-1.rs
+++ b/src/test/compile-fail/range-1.rs
@@ -22,6 +22,6 @@ pub fn main() {
     // Unsized type.
     let arr: &[_] = &[1, 2, 3];
     let range = *arr..;
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
-    //~| ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
+    //~| ERROR the trait `std::marker::Sized` is not implemented
 }
diff --git a/src/test/compile-fail/repeat-to-run-dtor-twice.rs b/src/test/compile-fail/repeat-to-run-dtor-twice.rs
index c8457adb8d6e6..0a55fe9f94279 100644
--- a/src/test/compile-fail/repeat-to-run-dtor-twice.rs
+++ b/src/test/compile-fail/repeat-to-run-dtor-twice.rs
@@ -25,5 +25,5 @@ impl Drop for Foo {
 fn main() {
     let a = Foo { x: 3 };
     let _ = [ a; 5 ];
-    //~^ ERROR the trait `core::marker::Copy` is not implemented for the type `Foo`
+    //~^ ERROR the trait `std::marker::Copy` is not implemented for the type `Foo`
 }
diff --git a/src/test/compile-fail/sized-cycle-note.rs b/src/test/compile-fail/sized-cycle-note.rs
index bb1ab2eafb355..ec378d05ba5ad 100644
--- a/src/test/compile-fail/sized-cycle-note.rs
+++ b/src/test/compile-fail/sized-cycle-note.rs
@@ -20,10 +20,10 @@ struct Baz { q: Option<Foo> }
 
 struct Foo { q: Option<Baz> }
 //~^ ERROR recursive type `Foo` has infinite size
-//~| type `Foo` is embedded within `core::option::Option<Foo>`...
-//~| ...which in turn is embedded within `core::option::Option<Foo>`...
+//~| type `Foo` is embedded within `std::option::Option<Foo>`...
+//~| ...which in turn is embedded within `std::option::Option<Foo>`...
 //~| ...which in turn is embedded within `Baz`...
-//~| ...which in turn is embedded within `core::option::Option<Baz>`...
+//~| ...which in turn is embedded within `std::option::Option<Baz>`...
 //~| ...which in turn is embedded within `Foo`, completing the cycle.
 
 impl Foo { fn bar(&self) {} }
diff --git a/src/test/compile-fail/str-idx.rs b/src/test/compile-fail/str-idx.rs
index 6e48ae20d09f3..6af731caaba40 100644
--- a/src/test/compile-fail/str-idx.rs
+++ b/src/test/compile-fail/str-idx.rs
@@ -10,5 +10,5 @@
 
 pub fn main() {
     let s: &str = "hello";
-    let c: u8 = s[4]; //~ ERROR the trait `core::ops::Index<_>` is not implemented
+    let c: u8 = s[4]; //~ ERROR the trait `std::ops::Index<_>` is not implemented
 }
diff --git a/src/test/compile-fail/str-mut-idx.rs b/src/test/compile-fail/str-mut-idx.rs
index ec6a14778a463..1fbdb3fddce6d 100644
--- a/src/test/compile-fail/str-mut-idx.rs
+++ b/src/test/compile-fail/str-mut-idx.rs
@@ -12,11 +12,11 @@ fn bot<T>() -> T { loop {} }
 
 fn mutate(s: &mut str) {
     s[1..2] = bot();
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `str`
-    //~| ERROR `core::marker::Sized` is not implemented for the type `str`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `str`
+    //~| ERROR `std::marker::Sized` is not implemented for the type `str`
     s[1usize] = bot();
-    //~^ ERROR `core::ops::Index<usize>` is not implemented for the type `str`
-    //~| ERROR `core::ops::IndexMut<usize>` is not implemented for the type `str`
+    //~^ ERROR `std::ops::Index<usize>` is not implemented for the type `str`
+    //~| ERROR `std::ops::IndexMut<usize>` is not implemented for the type `str`
 }
 
 pub fn main() {}
diff --git a/src/test/compile-fail/tag-that-dare-not-speak-its-name.rs b/src/test/compile-fail/tag-that-dare-not-speak-its-name.rs
index 660c1fa9a88d8..725234dfeab56 100644
--- a/src/test/compile-fail/tag-that-dare-not-speak-its-name.rs
+++ b/src/test/compile-fail/tag-that-dare-not-speak-its-name.rs
@@ -22,7 +22,7 @@ fn main() {
     let x : char = last(y);
     //~^ ERROR mismatched types
     //~| expected `char`
-    //~| found `core::option::Option<_>`
+    //~| found `std::option::Option<_>`
     //~| expected char
-    //~| found enum `core::option::Option`
+    //~| found enum `std::option::Option`
 }
diff --git a/src/test/compile-fail/task-rng-isnt-sendable.rs b/src/test/compile-fail/task-rng-isnt-sendable.rs
index 65801a5704b97..6d1a3ee794019 100644
--- a/src/test/compile-fail/task-rng-isnt-sendable.rs
+++ b/src/test/compile-fail/task-rng-isnt-sendable.rs
@@ -16,5 +16,5 @@ fn test_send<S: Send>() {}
 
 pub fn main() {
     test_send::<rand::ThreadRng>();
-    //~^ ERROR `core::marker::Send` is not implemented
+    //~^ ERROR `std::marker::Send` is not implemented
 }
diff --git a/src/test/compile-fail/trait-bounds-impl-comparison-1.rs b/src/test/compile-fail/trait-bounds-impl-comparison-1.rs
index a2369f8ffb4f2..fd0c2ddb5025d 100644
--- a/src/test/compile-fail/trait-bounds-impl-comparison-1.rs
+++ b/src/test/compile-fail/trait-bounds-impl-comparison-1.rs
@@ -34,7 +34,7 @@ trait Foo {
 impl Foo for isize {
     // invalid bound for T, was defined as Eq in trait
     fn test_error1_fn<T: Ord>(&self) {}
-    //~^ ERROR the requirement `T : core::cmp::Ord` appears on the impl
+    //~^ ERROR the requirement `T : std::cmp::Ord` appears on the impl
 
     // invalid bound for T, was defined as Eq + Ord in trait
     fn test_error2_fn<T: Eq + B>(&self) {}
@@ -58,7 +58,7 @@ impl Foo for isize {
     fn test6_fn<T: A>(&self) {}
 
     fn test_error7_fn<T: A + Eq>(&self) {}
-    //~^ ERROR the requirement `T : core::cmp::Eq` appears on the impl
+    //~^ ERROR the requirement `T : std::cmp::Eq` appears on the impl
 
     fn test_error8_fn<T: C>(&self) {}
     //~^ ERROR the requirement `T : C` appears on the impl
diff --git a/src/test/compile-fail/trait-bounds-not-on-bare-trait.rs b/src/test/compile-fail/trait-bounds-not-on-bare-trait.rs
index e126a3040e992..f70b2a9047425 100644
--- a/src/test/compile-fail/trait-bounds-not-on-bare-trait.rs
+++ b/src/test/compile-fail/trait-bounds-not-on-bare-trait.rs
@@ -15,7 +15,7 @@ trait Foo {
 // This should emit the less confusing error, not the more confusing one.
 
 fn foo(_x: Foo + Send) {
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/traits-negative-impls.rs b/src/test/compile-fail/traits-negative-impls.rs
index c37f45dcf50bb..0eb4e230e1494 100644
--- a/src/test/compile-fail/traits-negative-impls.rs
+++ b/src/test/compile-fail/traits-negative-impls.rs
@@ -31,8 +31,8 @@ fn dummy() {
     impl !Send for TestType {}
 
     Outer(TestType);
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type `dummy::TestType`
-    //~| ERROR the trait `core::marker::Send` is not implemented for the type `dummy::TestType`
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type `dummy::TestType`
+    //~| ERROR the trait `std::marker::Send` is not implemented for the type `dummy::TestType`
 }
 
 fn dummy1b() {
@@ -40,7 +40,7 @@ fn dummy1b() {
     impl !Send for TestType {}
 
     is_send(TestType);
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type `dummy1b::TestType`
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type `dummy1b::TestType`
 }
 
 fn dummy1c() {
@@ -48,7 +48,7 @@ fn dummy1c() {
     impl !Send for TestType {}
 
     is_send((8, TestType));
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type `dummy1c::TestType`
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type `dummy1c::TestType`
 }
 
 fn dummy2() {
@@ -56,7 +56,7 @@ fn dummy2() {
     impl !Send for TestType {}
 
     is_send(Box::new(TestType));
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type `dummy2::TestType`
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type `dummy2::TestType`
 }
 
 fn dummy3() {
@@ -64,7 +64,7 @@ fn dummy3() {
     impl !Send for TestType {}
 
     is_send(Box::new(Outer2(TestType)));
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type `dummy3::TestType`
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type `dummy3::TestType`
 }
 
 fn main() {
@@ -74,5 +74,5 @@ fn main() {
     // This will complain about a missing Send impl because `Sync` is implement *just*
     // for T that are `Send`. Look at #20366 and #19950
     is_sync(Outer2(TestType));
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type `main::TestType`
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type `main::TestType`
 }
diff --git a/src/test/compile-fail/trivial_casts.rs b/src/test/compile-fail/trivial_casts.rs
index 3119b865488e8..7693d98a2f7b0 100644
--- a/src/test/compile-fail/trivial_casts.rs
+++ b/src/test/compile-fail/trivial_casts.rs
@@ -76,7 +76,7 @@ pub fn main() {
 
     // functions
     fn baz(_x: i32) {}
-    let _ = &baz as &Fn(i32); //~ERROR trivial cast: `&fn(i32) {main::baz}` as `&core::ops::Fn(i32)`
+    let _ = &baz as &Fn(i32); //~ERROR trivial cast: `&fn(i32) {main::baz}` as `&std::ops::Fn(i32)`
     let _: &Fn(i32) = &baz;
     let x = |_x: i32| {};
     let _ = &x as &Fn(i32); //~ERROR trivial cast
diff --git a/src/test/compile-fail/typeck-default-trait-impl-negation-send.rs b/src/test/compile-fail/typeck-default-trait-impl-negation-send.rs
index db4d1fe485b32..58519e4df7550 100644
--- a/src/test/compile-fail/typeck-default-trait-impl-negation-send.rs
+++ b/src/test/compile-fail/typeck-default-trait-impl-negation-send.rs
@@ -27,5 +27,5 @@ fn is_send<T: Send>() {}
 fn main() {
     is_send::<MySendable>();
     is_send::<MyNotSendable>();
-    //~^ ERROR the trait `core::marker::Send` is not implemented for the type `MyNotSendable`
+    //~^ ERROR the trait `std::marker::Send` is not implemented for the type `MyNotSendable`
 }
diff --git a/src/test/compile-fail/typeck-default-trait-impl-negation-sync.rs b/src/test/compile-fail/typeck-default-trait-impl-negation-sync.rs
index 7c5d1d93b1a7f..8d174271a369f 100644
--- a/src/test/compile-fail/typeck-default-trait-impl-negation-sync.rs
+++ b/src/test/compile-fail/typeck-default-trait-impl-negation-sync.rs
@@ -43,11 +43,11 @@ fn is_sync<T: Sync>() {}
 fn main() {
     is_sync::<MySync>();
     is_sync::<MyNotSync>();
-    //~^ ERROR the trait `core::marker::Sync` is not implemented for the type `MyNotSync`
+    //~^ ERROR the trait `std::marker::Sync` is not implemented for the type `MyNotSync`
 
     is_sync::<MyTypeWUnsafe>();
-    //~^ ERROR the trait `core::marker::Sync` is not implemented for the type `core::cell::UnsafeCell<u8>`
+    //~^ ERROR the trait `std::marker::Sync` is not implemented for the type `std::cell::UnsafeCell<u8>`
 
     is_sync::<MyTypeManaged>();
-    //~^ ERROR the trait `core::marker::Sync` is not implemented for the type `Managed`
+    //~^ ERROR the trait `std::marker::Sync` is not implemented for the type `Managed`
 }
diff --git a/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause-2.rs b/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause-2.rs
index ad58ae92b46e2..c624ba425e47f 100644
--- a/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause-2.rs
+++ b/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause-2.rs
@@ -29,7 +29,7 @@ fn bar<T:NotImplemented>() { }
 
 fn test() {
     bar::<Option<i32>>();
-    //~^ ERROR the trait `NotImplemented` is not implemented for the type `core::option::Option<i32>`
+    //~^ ERROR the trait `NotImplemented` is not implemented for the type `std::option::Option<i32>`
 }
 
 fn main() {
diff --git a/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause.rs b/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause.rs
index ff8fbd4957491..c1757d124da55 100644
--- a/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause.rs
+++ b/src/test/compile-fail/typeck-default-trait-impl-trait-where-clause.rs
@@ -26,7 +26,7 @@ impl NotImplemented for i32 {}
 impl MyTrait for .. {}
 
 fn foo<T:MyTrait>() {
-    //~^ ERROR the trait `NotImplemented` is not implemented for the type `core::option::Option<T>`
+    //~^ ERROR the trait `NotImplemented` is not implemented for the type `std::option::Option<T>`
     // This should probably typecheck. This is #20671.
 }
 
diff --git a/src/test/compile-fail/typeck-unsafe-always-share.rs b/src/test/compile-fail/typeck-unsafe-always-share.rs
index 1cb6bd048ccc3..a0d236a1c5183 100644
--- a/src/test/compile-fail/typeck-unsafe-always-share.rs
+++ b/src/test/compile-fail/typeck-unsafe-always-share.rs
@@ -27,16 +27,16 @@ fn test<T: Sync>(s: T) {}
 fn main() {
     let us = UnsafeCell::new(MySync{u: UnsafeCell::new(0)});
     test(us);
-    //~^ ERROR `core::marker::Sync` is not implemented
+    //~^ ERROR `std::marker::Sync` is not implemented
 
     let uns = UnsafeCell::new(NoSync);
     test(uns);
-    //~^ ERROR `core::marker::Sync` is not implemented
+    //~^ ERROR `std::marker::Sync` is not implemented
 
     let ms = MySync{u: uns};
     test(ms);
-    //~^ ERROR `core::marker::Sync` is not implemented
+    //~^ ERROR `std::marker::Sync` is not implemented
 
     test(NoSync);
-    //~^ ERROR `core::marker::Sync` is not implemented
+    //~^ ERROR `std::marker::Sync` is not implemented
 }
diff --git a/src/test/compile-fail/ufcs-qpath-self-mismatch.rs b/src/test/compile-fail/ufcs-qpath-self-mismatch.rs
index 8e60064beca17..c07374ceaf2fb 100644
--- a/src/test/compile-fail/ufcs-qpath-self-mismatch.rs
+++ b/src/test/compile-fail/ufcs-qpath-self-mismatch.rs
@@ -12,7 +12,7 @@ use std::ops::Add;
 
 fn main() {
     <i32 as Add<u32>>::add(1, 2);
-    //~^ ERROR the trait `core::ops::Add<u32>` is not implemented for the type `i32`
+    //~^ ERROR the trait `std::ops::Add<u32>` is not implemented for the type `i32`
     <i32 as Add<i32>>::add(1u32, 2);
     //~^ ERROR mismatched types
     <i32 as Add<i32>>::add(1, 2u32);
diff --git a/src/test/compile-fail/unique-unique-kind.rs b/src/test/compile-fail/unique-unique-kind.rs
index 86fe4da3429d0..82aa49aa7061d 100644
--- a/src/test/compile-fail/unique-unique-kind.rs
+++ b/src/test/compile-fail/unique-unique-kind.rs
@@ -17,5 +17,5 @@ fn main() {
     // FIXME (#22405): Replace `Box::new` with `box` here when/if possible.
     let i = Box::new(Rc::new(100));
     f(i);
-    //~^ ERROR `core::marker::Send` is not implemented
+    //~^ ERROR `std::marker::Send` is not implemented
 }
diff --git a/src/test/compile-fail/unique-vec-res.rs b/src/test/compile-fail/unique-vec-res.rs
index 6aa0834cb27df..ed606dae55f21 100644
--- a/src/test/compile-fail/unique-vec-res.rs
+++ b/src/test/compile-fail/unique-vec-res.rs
@@ -35,8 +35,8 @@ fn main() {
     let r1 = vec!(Box::new(r { i: i1 }));
     let r2 = vec!(Box::new(r { i: i2 }));
     f(clone(&r1), clone(&r2));
-    //~^ ERROR the trait `core::clone::Clone` is not implemented for the type
-    //~^^ ERROR the trait `core::clone::Clone` is not implemented for the type
+    //~^ ERROR the trait `std::clone::Clone` is not implemented for the type
+    //~^^ ERROR the trait `std::clone::Clone` is not implemented for the type
     println!("{:?}", (r2, i1.get()));
     println!("{:?}", (r1, i2.get()));
 }
diff --git a/src/test/compile-fail/unsized-bare-typaram.rs b/src/test/compile-fail/unsized-bare-typaram.rs
index e28c082c80c4a..1885049f16937 100644
--- a/src/test/compile-fail/unsized-bare-typaram.rs
+++ b/src/test/compile-fail/unsized-bare-typaram.rs
@@ -9,5 +9,5 @@
 // except according to those terms.
 
 fn bar<T: Sized>() { }
-fn foo<T: ?Sized>() { bar::<T>() } //~ ERROR the trait `core::marker::Sized` is not implemented
+fn foo<T: ?Sized>() { bar::<T>() } //~ ERROR the trait `std::marker::Sized` is not implemented
 fn main() { }
diff --git a/src/test/compile-fail/unsized-enum.rs b/src/test/compile-fail/unsized-enum.rs
index df961978086e7..dad492eb24354 100644
--- a/src/test/compile-fail/unsized-enum.rs
+++ b/src/test/compile-fail/unsized-enum.rs
@@ -15,14 +15,14 @@ fn not_sized<T: ?Sized>() { }
 enum Foo<U> { FooSome(U), FooNone }
 fn foo1<T>() { not_sized::<Foo<T>>() } // Hunky dory.
 fn foo2<T: ?Sized>() { not_sized::<Foo<T>>() }
-//~^ ERROR the trait `core::marker::Sized` is not implemented
+//~^ ERROR the trait `std::marker::Sized` is not implemented
 //
 // Not OK: `T` is not sized.
 
 enum Bar<U: ?Sized> { BarSome(U), BarNone }
 fn bar1<T: ?Sized>() { not_sized::<Bar<T>>() }
 fn bar2<T: ?Sized>() { is_sized::<Bar<T>>() }
-//~^ ERROR the trait `core::marker::Sized` is not implemented
+//~^ ERROR the trait `std::marker::Sized` is not implemented
 //
 // Not OK: `Bar<T>` is not sized, but it should be.
 
diff --git a/src/test/compile-fail/unsized-struct.rs b/src/test/compile-fail/unsized-struct.rs
index 7b9fc2b468b78..c317850be1a6a 100644
--- a/src/test/compile-fail/unsized-struct.rs
+++ b/src/test/compile-fail/unsized-struct.rs
@@ -15,14 +15,14 @@ fn not_sized<T: ?Sized>() { }
 struct Foo<T> { data: T }
 fn foo1<T>() { not_sized::<Foo<T>>() } // Hunky dory.
 fn foo2<T: ?Sized>() { not_sized::<Foo<T>>() }
-//~^ ERROR the trait `core::marker::Sized` is not implemented
+//~^ ERROR the trait `std::marker::Sized` is not implemented
 //
 // Not OK: `T` is not sized.
 
 struct Bar<T: ?Sized> { data: T }
 fn bar1<T: ?Sized>() { not_sized::<Bar<T>>() }
 fn bar2<T: ?Sized>() { is_sized::<Bar<T>>() }
-//~^ ERROR the trait `core::marker::Sized` is not implemented
+//~^ ERROR the trait `std::marker::Sized` is not implemented
 //
 // Not OK: `Bar<T>` is not sized, but it should be.
 
diff --git a/src/test/compile-fail/unsized-trait-impl-trait-arg.rs b/src/test/compile-fail/unsized-trait-impl-trait-arg.rs
index 4723dfeaeb988..9cae2b5679929 100644
--- a/src/test/compile-fail/unsized-trait-impl-trait-arg.rs
+++ b/src/test/compile-fail/unsized-trait-impl-trait-arg.rs
@@ -16,7 +16,7 @@ trait T2<Z> {
 }
 struct S4<Y: ?Sized>(Box<Y>);
 impl<X: ?Sized> T2<X> for S4<X> {
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `X`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `X`
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/unsized3.rs b/src/test/compile-fail/unsized3.rs
index de1cbab82b281..acce00bd87ef5 100644
--- a/src/test/compile-fail/unsized3.rs
+++ b/src/test/compile-fail/unsized3.rs
@@ -15,7 +15,7 @@ use std::marker;
 // Unbounded.
 fn f1<X: ?Sized>(x: &X) {
     f2::<X>(x);
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
 }
 fn f2<X>(x: &X) {
 }
@@ -26,7 +26,7 @@ trait T {
 }
 fn f3<X: ?Sized + T>(x: &X) {
     f4::<X>(x);
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
 }
 fn f4<X: T>(x: &X) {
 }
@@ -40,7 +40,7 @@ fn f5<Y>(x: &Y) {}
 fn f6<X: ?Sized>(x: &X) {}
 fn f7<X: ?Sized>(x1: &E<X>, x2: &E<X>) {
     f5(x1);
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
     f6(x2); // ok
 }
 
@@ -52,19 +52,19 @@ struct S<X: ?Sized> {
 
 fn f8<X: ?Sized>(x1: &S<X>, x2: &S<X>) {
     f5(x1);
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
     f6(x2); // ok
 }
 
 // Test some tuples.
 fn f9<X: ?Sized>(x1: Box<S<X>>, x2: Box<E<X>>) {
     f5(&(*x1, 34));
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
 }
 
 fn f10<X: ?Sized>(x1: Box<S<X>>, x2: Box<E<X>>) {
     f5(&(32, *x2));
-    //~^ ERROR the trait `core::marker::Sized` is not implemented
+    //~^ ERROR the trait `std::marker::Sized` is not implemented
 }
 
 pub fn main() {
diff --git a/src/test/compile-fail/unsized5.rs b/src/test/compile-fail/unsized5.rs
index afa574bf85a8d..463ce2515ff80 100644
--- a/src/test/compile-fail/unsized5.rs
+++ b/src/test/compile-fail/unsized5.rs
@@ -11,27 +11,27 @@
 // Test `?Sized` types not allowed in fields (except the last one).
 
 struct S1<X: ?Sized> {
-    f1: X, //~ ERROR `core::marker::Sized` is not implemented
+    f1: X, //~ ERROR `std::marker::Sized` is not implemented
     f2: isize,
 }
 struct S2<X: ?Sized> {
     f: isize,
-    g: X, //~ ERROR `core::marker::Sized` is not implemented
+    g: X, //~ ERROR `std::marker::Sized` is not implemented
     h: isize,
 }
 struct S3 {
-    f: str, //~ ERROR `core::marker::Sized` is not implemented
+    f: str, //~ ERROR `std::marker::Sized` is not implemented
     g: [usize]
 }
 struct S4 {
-    f: [u8], //~ ERROR `core::marker::Sized` is not implemented
+    f: [u8], //~ ERROR `std::marker::Sized` is not implemented
     g: usize
 }
 enum E<X: ?Sized> {
-    V1(X, isize), //~ERROR `core::marker::Sized` is not implemented
+    V1(X, isize), //~ERROR `std::marker::Sized` is not implemented
 }
 enum F<X: ?Sized> {
-    V2{f1: X, f: isize}, //~ERROR `core::marker::Sized` is not implemented
+    V2{f1: X, f: isize}, //~ERROR `std::marker::Sized` is not implemented
 }
 
 pub fn main() {
diff --git a/src/test/compile-fail/unsized6.rs b/src/test/compile-fail/unsized6.rs
index 3f18f359d306e..4b55cdf25e58e 100644
--- a/src/test/compile-fail/unsized6.rs
+++ b/src/test/compile-fail/unsized6.rs
@@ -15,27 +15,27 @@ trait T {}
 fn f1<X: ?Sized>(x: &X) {
     let _: X; // <-- this is OK, no bindings created, no initializer.
     let _: (isize, (X, isize)); // same
-    let y: X; //~ERROR the trait `core::marker::Sized` is not implemented
-    let y: (isize, (X, isize)); //~ERROR the trait `core::marker::Sized` is not implemented
+    let y: X; //~ERROR the trait `std::marker::Sized` is not implemented
+    let y: (isize, (X, isize)); //~ERROR the trait `std::marker::Sized` is not implemented
 }
 fn f2<X: ?Sized + T>(x: &X) {
-    let y: X; //~ERROR the trait `core::marker::Sized` is not implemented
-    let y: (isize, (X, isize)); //~ERROR the trait `core::marker::Sized` is not implemented
+    let y: X; //~ERROR the trait `std::marker::Sized` is not implemented
+    let y: (isize, (X, isize)); //~ERROR the trait `std::marker::Sized` is not implemented
 }
 
 fn f3<X: ?Sized>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
-    let y: X = *x1; //~ERROR the trait `core::marker::Sized` is not implemented
-    let y = *x2; //~ERROR the trait `core::marker::Sized` is not implemented
-    let (y, z) = (*x3, 4); //~ERROR the trait `core::marker::Sized` is not implemented
+    let y: X = *x1; //~ERROR the trait `std::marker::Sized` is not implemented
+    let y = *x2; //~ERROR the trait `std::marker::Sized` is not implemented
+    let (y, z) = (*x3, 4); //~ERROR the trait `std::marker::Sized` is not implemented
 }
 fn f4<X: ?Sized + T>(x1: Box<X>, x2: Box<X>, x3: Box<X>) {
-    let y: X = *x1;         //~ERROR the trait `core::marker::Sized` is not implemented
-    let y = *x2;            //~ERROR the trait `core::marker::Sized` is not implemented
-    let (y, z) = (*x3, 4); //~ERROR the trait `core::marker::Sized` is not implemented
+    let y: X = *x1;         //~ERROR the trait `std::marker::Sized` is not implemented
+    let y = *x2;            //~ERROR the trait `std::marker::Sized` is not implemented
+    let (y, z) = (*x3, 4); //~ERROR the trait `std::marker::Sized` is not implemented
 }
 
-fn g1<X: ?Sized>(x: X) {} //~ERROR the trait `core::marker::Sized` is not implemented
-fn g2<X: ?Sized + T>(x: X) {} //~ERROR the trait `core::marker::Sized` is not implemented
+fn g1<X: ?Sized>(x: X) {} //~ERROR the trait `std::marker::Sized` is not implemented
+fn g2<X: ?Sized + T>(x: X) {} //~ERROR the trait `std::marker::Sized` is not implemented
 
 pub fn main() {
 }
diff --git a/src/test/compile-fail/unsized7.rs b/src/test/compile-fail/unsized7.rs
index 0245a1b5cf2c8..defa57414f409 100644
--- a/src/test/compile-fail/unsized7.rs
+++ b/src/test/compile-fail/unsized7.rs
@@ -20,7 +20,7 @@ trait T1<Z: T> {
 
 struct S3<Y: ?Sized>(Box<Y>);
 impl<X: ?Sized + T> T1<X> for S3<X> {
-    //~^ ERROR `core::marker::Sized` is not implemented for the type `X`
+    //~^ ERROR `std::marker::Sized` is not implemented for the type `X`
 }
 
 fn main() { }
diff --git a/src/test/compile-fail/where-clause-constraints-are-local-for-inherent-impl.rs b/src/test/compile-fail/where-clause-constraints-are-local-for-inherent-impl.rs
index 74342cfedd329..354407bc00203 100644
--- a/src/test/compile-fail/where-clause-constraints-are-local-for-inherent-impl.rs
+++ b/src/test/compile-fail/where-clause-constraints-are-local-for-inherent-impl.rs
@@ -21,7 +21,7 @@ impl<T> Foo<T> {
 
     fn fails_copy(self) {
         require_copy(self.x);
-        //~^ ERROR the trait `core::marker::Copy` is not implemented for the type `T`
+        //~^ ERROR the trait `std::marker::Copy` is not implemented for the type `T`
     }
 }
 
diff --git a/src/test/compile-fail/where-clause-constraints-are-local-for-trait-impl.rs b/src/test/compile-fail/where-clause-constraints-are-local-for-trait-impl.rs
index 8e01e89b68707..b747a555b5e7e 100644
--- a/src/test/compile-fail/where-clause-constraints-are-local-for-trait-impl.rs
+++ b/src/test/compile-fail/where-clause-constraints-are-local-for-trait-impl.rs
@@ -26,7 +26,7 @@ impl<T> Foo<T> for Bar<T> {
 
     fn fails_copy(self) {
         require_copy(self.x);
-        //~^ ERROR the trait `core::marker::Copy` is not implemented for the type `T`
+        //~^ ERROR the trait `std::marker::Copy` is not implemented for the type `T`
     }
 }
 
diff --git a/src/test/compile-fail/where-clauses-method-unsatisfied.rs b/src/test/compile-fail/where-clauses-method-unsatisfied.rs
index e5b54582e4e3f..c4d7d8207e74d 100644
--- a/src/test/compile-fail/where-clauses-method-unsatisfied.rs
+++ b/src/test/compile-fail/where-clauses-method-unsatisfied.rs
@@ -26,5 +26,5 @@ impl<T> Foo<T> {
 fn main() {
     let x = Foo { value: Bar };
     x.equals(&x);
-    //~^ ERROR the trait `core::cmp::Eq` is not implemented for the type `Bar`
+    //~^ ERROR the trait `std::cmp::Eq` is not implemented for the type `Bar`
 }
diff --git a/src/test/compile-fail/where-clauses-unsatisfied.rs b/src/test/compile-fail/where-clauses-unsatisfied.rs
index 269df212489cb..d1d0eb13d68df 100644
--- a/src/test/compile-fail/where-clauses-unsatisfied.rs
+++ b/src/test/compile-fail/where-clauses-unsatisfied.rs
@@ -15,5 +15,5 @@ struct Struct;
 
 fn main() {
     drop(equal(&Struct, &Struct))
-    //~^ ERROR the trait `core::cmp::Eq` is not implemented
+    //~^ ERROR the trait `std::cmp::Eq` is not implemented
 }
diff --git a/src/test/pretty/issue-4264.pp b/src/test/pretty/issue-4264.pp
index fe4337eedc63d..6ce534d52b883 100644
--- a/src/test/pretty/issue-4264.pp
+++ b/src/test/pretty/issue-4264.pp
@@ -39,42 +39,42 @@
 
 
     ((::std::fmt::format as
-         fn(core::fmt::Arguments<'_>) -> collections::string::String {collections::fmt::format})(((::std::fmt::Arguments::new_v1
-                                                                                                      as
-                                                                                                      fn(&[&str], &[core::fmt::ArgumentV1<'_>]) -> core::fmt::Arguments<'_> {core::fmt::Arguments<'_>::new_v1})(({
-                                                                                                                                                                                                                     static __STATIC_FMTSTR:
-                                                                                                                                                                                                                            &'static [&'static str]
-                                                                                                                                                                                                                            =
-                                                                                                                                                                                                                         (&([("test"
-                                                                                                                                                                                                                                 as
-                                                                                                                                                                                                                                 &'static str)]
-                                                                                                                                                                                                                               as
-                                                                                                                                                                                                                               [&'static str; 1])
-                                                                                                                                                                                                                             as
-                                                                                                                                                                                                                             &'static [&'static str; 1]);
-                                                                                                                                                                                                                     (__STATIC_FMTSTR
-                                                                                                                                                                                                                         as
-                                                                                                                                                                                                                         &'static [&'static str])
-                                                                                                                                                                                                                 }
-                                                                                                                                                                                                                    as
-                                                                                                                                                                                                                    &[&str]),
-                                                                                                                                                                                                                (&(match (()
-                                                                                                                                                                                                                             as
-                                                                                                                                                                                                                             ())
-                                                                                                                                                                                                                       {
-                                                                                                                                                                                                                       ()
-                                                                                                                                                                                                                       =>
-                                                                                                                                                                                                                       ([]
-                                                                                                                                                                                                                           as
-                                                                                                                                                                                                                           [core::fmt::ArgumentV1<'_>; 0]),
-                                                                                                                                                                                                                   }
-                                                                                                                                                                                                                      as
-                                                                                                                                                                                                                      [core::fmt::ArgumentV1<'_>; 0])
-                                                                                                                                                                                                                    as
-                                                                                                                                                                                                                    &[core::fmt::ArgumentV1<'_>; 0]))
-                                                                                                     as
-                                                                                                     core::fmt::Arguments<'_>))
-        as collections::string::String);
+         fn(std::fmt::Arguments<'_>) -> std::string::String {std::fmt::format})(((::std::fmt::Arguments::new_v1
+                                                                                     as
+                                                                                     fn(&[&str], &[std::fmt::ArgumentV1<'_>]) -> std::fmt::Arguments<'_> {std::fmt::Arguments<'_>::new_v1})(({
+                                                                                                                                                                                                 static __STATIC_FMTSTR:
+                                                                                                                                                                                                        &'static [&'static str]
+                                                                                                                                                                                                        =
+                                                                                                                                                                                                     (&([("test"
+                                                                                                                                                                                                             as
+                                                                                                                                                                                                             &'static str)]
+                                                                                                                                                                                                           as
+                                                                                                                                                                                                           [&'static str; 1])
+                                                                                                                                                                                                         as
+                                                                                                                                                                                                         &'static [&'static str; 1]);
+                                                                                                                                                                                                 (__STATIC_FMTSTR
+                                                                                                                                                                                                     as
+                                                                                                                                                                                                     &'static [&'static str])
+                                                                                                                                                                                             }
+                                                                                                                                                                                                as
+                                                                                                                                                                                                &[&str]),
+                                                                                                                                                                                            (&(match (()
+                                                                                                                                                                                                         as
+                                                                                                                                                                                                         ())
+                                                                                                                                                                                                   {
+                                                                                                                                                                                                   ()
+                                                                                                                                                                                                   =>
+                                                                                                                                                                                                   ([]
+                                                                                                                                                                                                       as
+                                                                                                                                                                                                       [std::fmt::ArgumentV1<'_>; 0]),
+                                                                                                                                                                                               }
+                                                                                                                                                                                                  as
+                                                                                                                                                                                                  [std::fmt::ArgumentV1<'_>; 0])
+                                                                                                                                                                                                as
+                                                                                                                                                                                                &[std::fmt::ArgumentV1<'_>; 0]))
+                                                                                    as
+                                                                                    std::fmt::Arguments<'_>))
+        as std::string::String);
 }
 pub type Foo = [i32; (3 as usize)];
 pub struct Bar {
diff --git a/src/test/run-make/json-errors/Makefile b/src/test/run-make/json-errors/Makefile
index cd3a2af30ab8f..bb73fda67bddb 100644
--- a/src/test/run-make/json-errors/Makefile
+++ b/src/test/run-make/json-errors/Makefile
@@ -7,4 +7,4 @@ all:
 	cd $(TMPDIR)
 	-$(RUSTC) -Z unstable-options --error-format=json foo.rs 2>$(LOG)
 	grep -q '{"message":"unresolved name `y`","code":{"code":"E0425","explanation":"\\nAn unresolved name was used. Example of erroneous codes.*"},"level":"error","spans":\[{"file_name":"foo.rs","byte_start":496,"byte_end":497,"line_start":12,"line_end":12,"column_start":18,"column_end":19,"text":\[{"text":"    let x = 42 + y;","highlight_start":18,"highlight_end":19}\]}\],"children":\[\]}' $(LOG)
-	grep -q '{"message":".*","code":{"code":"E0277","explanation":"\\nYou tried.*"},"level":"error","spans":\[{.*}\],"children":\[{"message":"the .*","code":null,"level":"help","spans":\[{"file_name":"foo.rs","byte_start":504,"byte_end":516,"line_start":14,"line_end":14,"column_start":0,"column_end":0,"text":\[{.*}\]}\],"children":\[\]},{"message":"  <u8 as core::ops::Add>","code":null,"level":"help",' $(LOG)
+	grep -q '{"message":".*","code":{"code":"E0277","explanation":"\\nYou tried.*"},"level":"error","spans":\[{.*}\],"children":\[{"message":"the .*","code":null,"level":"help","spans":\[{"file_name":"foo.rs","byte_start":504,"byte_end":516,"line_start":14,"line_end":14,"column_start":0,"column_end":0,"text":\[{.*}\]}\],"children":\[\]},{"message":"  <u8 as std::ops::Add>","code":null,"level":"help",' $(LOG)
diff --git a/src/test/run-pass/issue-21058.rs b/src/test/run-pass/issue-21058.rs
index 0ca936878148b..af767464db351 100644
--- a/src/test/run-pass/issue-21058.rs
+++ b/src/test/run-pass/issue-21058.rs
@@ -26,5 +26,5 @@ fn main() {
         std::intrinsics::type_name::<NT>(),
         // DST
         std::intrinsics::type_name::<DST>()
-    )}, ("[u8]", "str", "core::marker::Send + 'static", "NT", "DST"));
+    )}, ("[u8]", "str", "std::marker::Send + 'static", "NT", "DST"));
 }