diff --git a/src/cargo/core/compiler/standard_lib.rs b/src/cargo/core/compiler/standard_lib.rs
index e04627f43d7..214b4b43703 100644
--- a/src/cargo/core/compiler/standard_lib.rs
+++ b/src/cargo/core/compiler/standard_lib.rs
@@ -7,10 +7,9 @@ use crate::core::resolver::features::{FeaturesFor, ResolvedFeatures};
 use crate::core::resolver::{HasDevUnits, ResolveOpts};
 use crate::core::{Dependency, PackageId, PackageSet, Resolve, SourceId, Workspace};
 use crate::ops::{self, Packages};
-use crate::util::errors::{CargoResult, CargoResultExt};
+use crate::util::errors::CargoResult;
 use std::collections::{HashMap, HashSet};
 use std::env;
-use std::fs;
 use std::path::PathBuf;
 
 /// Parse the `-Zbuild-std` flag.
@@ -39,48 +38,28 @@ pub fn resolve_std<'cfg>(
     crates: &[String],
 ) -> CargoResult<(PackageSet<'cfg>, Resolve, ResolvedFeatures)> {
     let src_path = detect_sysroot_src_path(target_data)?;
-
-    // Special std packages should be pulled from `library/` and should be
-    // prefixed with `rustc-std-workspace-` in certain places.
-    let libs_prefix = "library/";
-    let special_std_prefix = "rustc-std-workspace-";
-    let libs_path = src_path.join(libs_prefix);
-
-    // Crates in rust-src to build. libtest is in some sense the "root" package
-    // of std, as nothing else depends on it, so it must be explicitly added.
-    let mut members = vec![format!("{}test", libs_prefix)];
-
-    // If rust-src contains a "vendor" directory, then patch in all the crates it contains.
-    let vendor_path = src_path.join("vendor");
-    let vendor_dir = fs::read_dir(&vendor_path)
-        .chain_err(|| format!("could not read vendor path {}", vendor_path.display()))?;
-    let patches = vendor_dir
-        .into_iter()
-        .map(|entry| {
-            let entry = entry?;
-            let name = entry
-                .file_name()
-                .into_string()
-                .map_err(|_| anyhow::anyhow!("package name wasn't utf8"))?;
-
-            // Remap the rustc-std-workspace crates to the actual rust-src libraries
-            let path = if let Some(real_name) = name.strip_prefix(special_std_prefix) {
-                // Record this crate as something to build in the workspace
-                members.push(format!("{}{}", libs_prefix, real_name));
-                libs_path.join(&name)
-            } else {
-                entry.path()
-            };
-            let source_path = SourceId::for_path(&path)?;
-            let dep = Dependency::parse_no_deprecated(&name, None, source_path)?;
+    let to_patch = [
+        "rustc-std-workspace-core",
+        "rustc-std-workspace-alloc",
+        "rustc-std-workspace-std",
+    ];
+    let patches = to_patch
+        .iter()
+        .map(|&name| {
+            let source_path = SourceId::for_path(&src_path.join("library").join(name))?;
+            let dep = Dependency::parse_no_deprecated(name, None, source_path)?;
             Ok(dep)
         })
-        .collect::<CargoResult<Vec<_>>>()
-        .chain_err(|| "failed to generate vendor patches")?;
-
+        .collect::<CargoResult<Vec<_>>>()?;
     let crates_io_url = crate::sources::CRATES_IO_INDEX.parse().unwrap();
     let mut patch = HashMap::new();
     patch.insert(crates_io_url, patches);
+    let members = vec![
+        String::from("library/std"),
+        String::from("library/core"),
+        String::from("library/alloc"),
+        String::from("library/test"),
+    ];
     let ws_config = crate::core::WorkspaceConfig::Root(crate::core::WorkspaceRootConfig::new(
         &src_path,
         &Some(members),
diff --git a/tests/testsuite/mock-std/library/test/Cargo.toml b/tests/testsuite/mock-std/library/test/Cargo.toml
index eb81bbf5e35..299db7bfd49 100644
--- a/tests/testsuite/mock-std/library/test/Cargo.toml
+++ b/tests/testsuite/mock-std/library/test/Cargo.toml
@@ -10,7 +10,6 @@ std = { path = "../std" }
 panic_unwind = { path = "../panic_unwind" }
 compiler_builtins = { path = "../compiler_builtins" }
 registry-dep-using-std = { version = "*", features = ['mockbuild'] }
-registry-dep-only-used-by-test = { version = "*" }
 
 [features]
 panic-unwind = []
diff --git a/tests/testsuite/mock-std/library/test/src/lib.rs b/tests/testsuite/mock-std/library/test/src/lib.rs
index 224b89bb255..a112855f536 100644
--- a/tests/testsuite/mock-std/library/test/src/lib.rs
+++ b/tests/testsuite/mock-std/library/test/src/lib.rs
@@ -7,5 +7,4 @@ extern crate test;
 pub use test::*;
 
 pub fn custom_api() {
-    registry_dep_only_used_by_test::wow_testing_is_so_easy();
 }
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-only-used-by-test/Cargo.toml b/tests/testsuite/mock-std/vendor/registry-dep-only-used-by-test/Cargo.toml
deleted file mode 100644
index 31ba65a984b..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-only-used-by-test/Cargo.toml
+++ /dev/null
@@ -1,9 +0,0 @@
-[package]
-name = "registry-dep-only-used-by-test"
-version = "1.0.0"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
-edition = "2018"
-
-[dependencies]
-
-[features]
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-only-used-by-test/src/lib.rs b/tests/testsuite/mock-std/vendor/registry-dep-only-used-by-test/src/lib.rs
deleted file mode 100644
index a68d2aeef15..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-only-used-by-test/src/lib.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-pub fn wow_testing_is_so_easy() {
-}
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-using-alloc/Cargo.toml b/tests/testsuite/mock-std/vendor/registry-dep-using-alloc/Cargo.toml
deleted file mode 100644
index f7e4ab23292..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-using-alloc/Cargo.toml
+++ /dev/null
@@ -1,12 +0,0 @@
-[package]
-name = "registry-dep-using-alloc"
-version = "1.0.0"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
-edition = "2018"
-
-[dependencies]
-rustc-std-workspace-alloc = { version = "*", optional = true }
-rustc-std-workspace-core = { version = "*", optional = true }
-
-[features]
-mockbuild = ["rustc-std-workspace-alloc", "rustc-std-workspace-core"]
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-using-alloc/src/lib.rs b/tests/testsuite/mock-std/vendor/registry-dep-using-alloc/src/lib.rs
deleted file mode 100644
index b9ab3033984..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-using-alloc/src/lib.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-#[cfg(feature = "mockbuild")]
-pub fn custom_api() {
-}
-
-#[cfg(not(feature = "mockbuild"))]
-pub fn non_sysroot_api() {
-    core::custom_api();
-    alloc::custom_api();
-}
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-using-core/Cargo.toml b/tests/testsuite/mock-std/vendor/registry-dep-using-core/Cargo.toml
deleted file mode 100644
index befb83a63d7..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-using-core/Cargo.toml
+++ /dev/null
@@ -1,11 +0,0 @@
-[package]
-name = "registry-dep-using-core"
-version = "1.0.0"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
-edition = "2018"
-
-[dependencies]
-rustc-std-workspace-core = { version = "*", optional = true }
-
-[features]
-mockbuild = ["rustc-std-workspace-core"]
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-using-core/src/lib.rs b/tests/testsuite/mock-std/vendor/registry-dep-using-core/src/lib.rs
deleted file mode 100644
index f9dbac0f45a..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-using-core/src/lib.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-#[cfg(feature = "mockbuild")]
-pub fn custom_api() {
-}
-
-#[cfg(not(feature = "mockbuild"))]
-pub fn non_sysroot_api() {
-    core::custom_api();
-}
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-using-std/Cargo.toml b/tests/testsuite/mock-std/vendor/registry-dep-using-std/Cargo.toml
deleted file mode 100644
index 71ef0a42f0d..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-using-std/Cargo.toml
+++ /dev/null
@@ -1,11 +0,0 @@
-[package]
-name = "registry-dep-using-std"
-version = "1.0.0"
-authors = ["Alex Crichton <alex@alexcrichton.com>"]
-edition = "2018"
-
-[dependencies]
-rustc-std-workspace-std = { version = "*", optional = true }
-
-[features]
-mockbuild = ["rustc-std-workspace-std"]
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/registry-dep-using-std/src/lib.rs b/tests/testsuite/mock-std/vendor/registry-dep-using-std/src/lib.rs
deleted file mode 100644
index f3af3917848..00000000000
--- a/tests/testsuite/mock-std/vendor/registry-dep-using-std/src/lib.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-#[cfg(feature = "mockbuild")]
-pub fn custom_api() {
-}
-
-#[cfg(not(feature = "mockbuild"))]
-pub fn non_sysroot_api() {
-    std::custom_api();
-}
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/rustc-std-workspace-alloc/Cargo.toml b/tests/testsuite/mock-std/vendor/rustc-std-workspace-alloc/Cargo.toml
deleted file mode 100644
index 4465a08a82b..00000000000
--- a/tests/testsuite/mock-std/vendor/rustc-std-workspace-alloc/Cargo.toml
+++ /dev/null
@@ -1 +0,0 @@
-this file shouldn't be read 
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/rustc-std-workspace-core/Cargo.toml b/tests/testsuite/mock-std/vendor/rustc-std-workspace-core/Cargo.toml
deleted file mode 100644
index 4465a08a82b..00000000000
--- a/tests/testsuite/mock-std/vendor/rustc-std-workspace-core/Cargo.toml
+++ /dev/null
@@ -1 +0,0 @@
-this file shouldn't be read 
\ No newline at end of file
diff --git a/tests/testsuite/mock-std/vendor/rustc-std-workspace-std/Cargo.toml b/tests/testsuite/mock-std/vendor/rustc-std-workspace-std/Cargo.toml
deleted file mode 100644
index 4465a08a82b..00000000000
--- a/tests/testsuite/mock-std/vendor/rustc-std-workspace-std/Cargo.toml
+++ /dev/null
@@ -1 +0,0 @@
-this file shouldn't be read 
\ No newline at end of file
diff --git a/tests/testsuite/standard_lib.rs b/tests/testsuite/standard_lib.rs
index 2e0adf92aa1..1473955b79f 100644
--- a/tests/testsuite/standard_lib.rs
+++ b/tests/testsuite/standard_lib.rs
@@ -27,18 +27,71 @@ fn setup() -> Option<Setup> {
         return None;
     }
 
-    // Register a version of one of the std dependencies that doesn't compile.
-    // This ensures that the mock-std's vendor is actually being used.
+    // Our mock sysroot requires a few packages from crates.io, so make sure
+    // they're "published" to crates.io. Also edit their code a bit to make sure
+    // that they have access to our custom crates with custom apis.
     Package::new("registry-dep-using-core", "1.0.0")
         .file(
             "src/lib.rs",
             "
-               don't compile me bro!!
+                #![no_std]
+
+                #[cfg(feature = \"mockbuild\")]
+                pub fn custom_api() {
+                }
+
+                #[cfg(not(feature = \"mockbuild\"))]
+                pub fn non_sysroot_api() {
+                    core::custom_api();
+                }
             ",
         )
         .add_dep(Dependency::new("rustc-std-workspace-core", "*").optional(true))
         .feature("mockbuild", &["rustc-std-workspace-core"])
         .publish();
+    Package::new("registry-dep-using-alloc", "1.0.0")
+        .file(
+            "src/lib.rs",
+            "
+                #![no_std]
+
+                extern crate alloc;
+
+                #[cfg(feature = \"mockbuild\")]
+                pub fn custom_api() {
+                }
+
+                #[cfg(not(feature = \"mockbuild\"))]
+                pub fn non_sysroot_api() {
+                    core::custom_api();
+                    alloc::custom_api();
+                }
+            ",
+        )
+        .add_dep(Dependency::new("rustc-std-workspace-core", "*").optional(true))
+        .add_dep(Dependency::new("rustc-std-workspace-alloc", "*").optional(true))
+        .feature(
+            "mockbuild",
+            &["rustc-std-workspace-core", "rustc-std-workspace-alloc"],
+        )
+        .publish();
+    Package::new("registry-dep-using-std", "1.0.0")
+        .file(
+            "src/lib.rs",
+            "
+                #[cfg(feature = \"mockbuild\")]
+                pub fn custom_api() {
+                }
+
+                #[cfg(not(feature = \"mockbuild\"))]
+                pub fn non_sysroot_api() {
+                    std::custom_api();
+                }
+            ",
+        )
+        .add_dep(Dependency::new("rustc-std-workspace-std", "*").optional(true))
+        .feature("mockbuild", &["rustc-std-workspace-std"])
+        .publish();
 
     let p = ProjectBuilder::new(paths::root().join("rustc-wrapper"))
         .file(
@@ -282,81 +335,6 @@ fn depend_same_as_std() {
         None => return,
     };
 
-    // Our mock sysroot requires a few packages from crates.io, so make sure
-    // they're "published" to crates.io. Also edit their code a bit to make sure
-    // that they have access to our custom crates with custom apis.
-    Package::new("registry-dep-using-core", "1.0.0")
-        .file(
-            "src/lib.rs",
-            "
-                #![no_std]
-
-                #[cfg(feature = \"mockbuild\")]
-                pub fn custom_api() {
-                }
-
-                #[cfg(not(feature = \"mockbuild\"))]
-                pub fn non_sysroot_api() {
-                    core::custom_api();
-                }
-            ",
-        )
-        .add_dep(Dependency::new("rustc-std-workspace-core", "*").optional(true))
-        .feature("mockbuild", &["rustc-std-workspace-core"])
-        .publish();
-    Package::new("registry-dep-using-alloc", "1.0.0")
-        .file(
-            "src/lib.rs",
-            "
-                #![no_std]
-
-                extern crate alloc;
-
-                #[cfg(feature = \"mockbuild\")]
-                pub fn custom_api() {
-                }
-
-                #[cfg(not(feature = \"mockbuild\"))]
-                pub fn non_sysroot_api() {
-                    core::custom_api();
-                    alloc::custom_api();
-                }
-            ",
-        )
-        .add_dep(Dependency::new("rustc-std-workspace-core", "*").optional(true))
-        .add_dep(Dependency::new("rustc-std-workspace-alloc", "*").optional(true))
-        .feature(
-            "mockbuild",
-            &["rustc-std-workspace-core", "rustc-std-workspace-alloc"],
-        )
-        .publish();
-    Package::new("registry-dep-using-std", "1.0.0")
-        .file(
-            "src/lib.rs",
-            "
-                #[cfg(feature = \"mockbuild\")]
-                pub fn custom_api() {
-                }
-
-                #[cfg(not(feature = \"mockbuild\"))]
-                pub fn non_sysroot_api() {
-                    std::custom_api();
-                }
-            ",
-        )
-        .add_dep(Dependency::new("rustc-std-workspace-std", "*").optional(true))
-        .feature("mockbuild", &["rustc-std-workspace-std"])
-        .publish();
-    Package::new("registry-dep-only-used-by-test", "1.0.0")
-        .file(
-            "src/lib.rs",
-            "
-                pub fn wow_testing_is_so_easy() {
-                }
-            ",
-        )
-        .publish();
-
     let p = project()
         .file(
             "src/lib.rs",
@@ -689,11 +667,6 @@ fn no_roots() {
     p.cargo("build")
         .build_std(&setup)
         .target_host()
-        .with_stderr(
-            "\
-[UPDATING] [..]
-[FINISHED] [..]
-",
-        )
+        .with_stderr_contains("[FINISHED] [..]")
         .run();
 }