diff --git a/compiler/rustc_driver_impl/Cargo.toml b/compiler/rustc_driver_impl/Cargo.toml
index 242aa06fe3e3c..fcc0afd3488b0 100644
--- a/compiler/rustc_driver_impl/Cargo.toml
+++ b/compiler/rustc_driver_impl/Cargo.toml
@@ -50,7 +50,7 @@ rustc_trait_selection = { path = "../rustc_trait_selection" }
 rustc_ty_utils = { path = "../rustc_ty_utils" }
 serde_json = "1.0.59"
 shlex = "1.0"
-time = { version = "0.3", default-features = false, features = ["alloc", "formatting"] }
+time = { version = "0.3", default-features = false, features = ["alloc", "formatting", "parsing", "macros"] }
 tracing = { version = "0.1.35" }
 # tidy-alphabetical-end
 
diff --git a/compiler/rustc_driver_impl/messages.ftl b/compiler/rustc_driver_impl/messages.ftl
index 39462112dc287..1b69a6e2fbecc 100644
--- a/compiler/rustc_driver_impl/messages.ftl
+++ b/compiler/rustc_driver_impl/messages.ftl
@@ -1,6 +1,10 @@
 driver_impl_ice = the compiler unexpectedly panicked. this is a bug.
 driver_impl_ice_bug_report = we would appreciate a bug report: {$bug_report_url}
 driver_impl_ice_bug_report_internal_feature = using internal features is not supported and expected to cause internal compiler errors when used incorrectly
+driver_impl_ice_bug_report_outdated =
+    it seems that this compiler `{$version}` is outdated, a newer nightly should have been released in the mean time
+    .update = please consider running `rustup update nightly` to update the nightly channel and check if this problem still persists
+    .url = if the problem still persists, we would appreciate a bug report: {$bug_report_url}
 driver_impl_ice_exclude_cargo_defaults = some of the compiler flags provided by cargo are hidden
 
 driver_impl_ice_flags = compiler flags: {$flags}
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index ab1e37e4ac221..85be97ea24fdf 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -58,7 +58,7 @@ use std::str;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, OnceLock};
 use std::time::{Instant, SystemTime};
-use time::OffsetDateTime;
+use time::{Date, OffsetDateTime, Time};
 
 #[allow(unused_macros)]
 macro do_not_use_print($($t:tt)*) {
@@ -1369,6 +1369,9 @@ pub fn install_ice_hook(
     using_internal_features
 }
 
+const DATE_FORMAT: &[time::format_description::FormatItem<'static>] =
+    &time::macros::format_description!("[year]-[month]-[day]");
+
 /// Prints the ICE message, including query stack, but without backtrace.
 ///
 /// The message will point the user at `bug_report_url` to report the ICE.
@@ -1397,10 +1400,34 @@ fn report_ice(
         dcx.emit_err(session_diagnostics::Ice);
     }
 
-    if using_internal_features.load(std::sync::atomic::Ordering::Relaxed) {
-        dcx.emit_note(session_diagnostics::IceBugReportInternalFeature);
+    use time::ext::NumericalDuration;
+
+    // Try to hint user to update nightly if applicable when reporting an ICE.
+    // Attempt to calculate when current version was released, and add 12 hours
+    // as buffer. If the current version's release timestamp is older than
+    // the system's current time + 24 hours + 12 hours buffer if we're on
+    // nightly.
+    if let Some("nightly") = option_env!("CFG_RELEASE_CHANNEL")
+        && let Some(version) = option_env!("CFG_VERSION")
+        && let Some(ver_date_str) = option_env!("CFG_VER_DATE")
+        && let Ok(ver_date) = Date::parse(&ver_date_str, DATE_FORMAT)
+        && let ver_datetime = OffsetDateTime::new_utc(ver_date, Time::MIDNIGHT)
+        && let system_datetime = OffsetDateTime::from(SystemTime::now())
+        && system_datetime.checked_sub(36.hours()).is_some_and(|d| d > ver_datetime)
+        && !using_internal_features.load(std::sync::atomic::Ordering::Relaxed)
+    {
+        dcx.emit_note(session_diagnostics::IceBugReportOutdated {
+            version,
+            bug_report_url,
+            note_update: (),
+            note_url: (),
+        });
     } else {
-        dcx.emit_note(session_diagnostics::IceBugReport { bug_report_url });
+        if using_internal_features.load(std::sync::atomic::Ordering::Relaxed) {
+            dcx.emit_note(session_diagnostics::IceBugReportInternalFeature);
+        } else {
+            dcx.emit_note(session_diagnostics::IceBugReport { bug_report_url });
+        }
     }
 
     let version = util::version_str!().unwrap_or("unknown_version");
diff --git a/compiler/rustc_driver_impl/src/session_diagnostics.rs b/compiler/rustc_driver_impl/src/session_diagnostics.rs
index 2b31fdd77cca3..62d0da62d2a79 100644
--- a/compiler/rustc_driver_impl/src/session_diagnostics.rs
+++ b/compiler/rustc_driver_impl/src/session_diagnostics.rs
@@ -46,6 +46,17 @@ pub(crate) struct IceBugReport<'a> {
 #[diag(driver_impl_ice_bug_report_internal_feature)]
 pub(crate) struct IceBugReportInternalFeature;
 
+#[derive(Diagnostic)]
+#[diag(driver_impl_ice_bug_report_outdated)]
+pub(crate) struct IceBugReportOutdated<'a> {
+    pub version: &'a str,
+    pub bug_report_url: &'a str,
+    #[note(driver_impl_update)]
+    pub note_update: (),
+    #[note(driver_impl_url)]
+    pub note_url: (),
+}
+
 #[derive(Diagnostic)]
 #[diag(driver_impl_ice_version)]
 pub(crate) struct IceVersion<'a> {
diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs
index 293d8f01e673a..57b8df52f4b79 100644
--- a/compiler/rustc_errors/src/emitter.rs
+++ b/compiler/rustc_errors/src/emitter.rs
@@ -10,7 +10,6 @@
 use rustc_span::source_map::SourceMap;
 use rustc_span::{FileLines, FileName, SourceFile, Span};
 
-use crate::error::TranslateError;
 use crate::snippet::{
     Annotation, AnnotationColumn, AnnotationType, Line, MultilineAnnotation, Style, StyledString,
 };
@@ -539,18 +538,9 @@ impl Emitter for HumanEmitter {
 /// Fatal diagnostics are forwarded to `fatal_dcx` to avoid silent
 /// failures of rustc, as witnessed e.g. in issue #89358.
 pub struct SilentEmitter {
+    pub fallback_bundle: LazyFallbackBundle,
     pub fatal_dcx: DiagCtxt,
-    pub fatal_note: String,
-}
-
-pub fn silent_translate<'a>(message: &'a DiagMessage) -> Result<Cow<'_, str>, TranslateError<'_>> {
-    match message {
-        DiagMessage::Str(msg) | DiagMessage::Translated(msg) => Ok(Cow::Borrowed(msg)),
-        DiagMessage::FluentIdentifier(identifier, _) => {
-            // Any value works here.
-            Ok(identifier.clone())
-        }
-    }
+    pub fatal_note: Option<String>,
 }
 
 impl Translate for SilentEmitter {
@@ -559,17 +549,9 @@ impl Translate for SilentEmitter {
     }
 
     fn fallback_fluent_bundle(&self) -> &FluentBundle {
-        panic!("silent emitter attempted to translate message")
-    }
-
-    // Override `translate_message` for the silent emitter because eager translation of
-    // subdiagnostics result in a call to this.
-    fn translate_message<'a>(
-        &'a self,
-        message: &'a DiagMessage,
-        _: &'a FluentArgs<'_>,
-    ) -> Result<Cow<'_, str>, TranslateError<'_>> {
-        silent_translate(message)
+        // Ideally this field wouldn't be necessary and the fallback bundle in `fatal_dcx` would be
+        // used but the lock prevents this.
+        &self.fallback_bundle
     }
 }
 
@@ -580,7 +562,9 @@ impl Emitter for SilentEmitter {
 
     fn emit_diagnostic(&mut self, mut diag: DiagInner) {
         if diag.level == Level::Fatal {
-            diag.sub(Level::Note, self.fatal_note.clone(), MultiSpan::new());
+            if let Some(fatal_note) = &self.fatal_note {
+                diag.sub(Level::Note, fatal_note.clone(), MultiSpan::new());
+            }
             self.fatal_dcx.emit_diagnostic(diag);
         }
     }
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 0a6d66f52dad0..0caa8fa9e8abe 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -63,7 +63,7 @@ use emitter::{is_case_difference, DynEmitter, Emitter};
 use registry::Registry;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet};
 use rustc_data_structures::stable_hasher::{Hash128, StableHasher};
-use rustc_data_structures::sync::Lock;
+use rustc_data_structures::sync::{Lock, Lrc};
 use rustc_data_structures::AtomicRef;
 use rustc_lint_defs::LintExpectationId;
 use rustc_span::source_map::SourceMap;
@@ -606,29 +606,54 @@ impl DiagCtxt {
     }
 
     pub fn new(emitter: Box<DynEmitter>) -> Self {
-        Self {
-            inner: Lock::new(DiagCtxtInner {
-                flags: DiagCtxtFlags { can_emit_warnings: true, ..Default::default() },
-                err_guars: Vec::new(),
-                lint_err_guars: Vec::new(),
-                delayed_bugs: Vec::new(),
-                deduplicated_err_count: 0,
-                deduplicated_warn_count: 0,
-                emitter,
-                must_produce_diag: false,
-                has_printed: false,
-                suppressed_expected_diag: false,
-                taught_diagnostics: Default::default(),
-                emitted_diagnostic_codes: Default::default(),
-                emitted_diagnostics: Default::default(),
-                stashed_diagnostics: Default::default(),
-                future_breakage_diagnostics: Vec::new(),
-                check_unstable_expect_diagnostics: false,
-                unstable_expect_diagnostics: Vec::new(),
-                fulfilled_expectations: Default::default(),
-                ice_file: None,
-            }),
+        Self { inner: Lock::new(DiagCtxtInner::new(emitter)) }
+    }
+
+    pub fn make_silent(&mut self, fallback_bundle: LazyFallbackBundle, fatal_note: Option<String>) {
+        self.wrap_emitter(|old_dcx| {
+            Box::new(emitter::SilentEmitter {
+                fallback_bundle,
+                fatal_dcx: DiagCtxt { inner: Lock::new(old_dcx) },
+                fatal_note,
+            })
+        });
+    }
+
+    fn wrap_emitter<F>(&mut self, f: F)
+    where
+        F: FnOnce(DiagCtxtInner) -> Box<DynEmitter>,
+    {
+        // A empty type that implements `Emitter` so that a `DiagCtxtInner` can be constructed
+        // to temporarily swap in place of the real one, which will be used in constructing
+        // its replacement.
+        struct FalseEmitter;
+
+        impl Emitter for FalseEmitter {
+            fn emit_diagnostic(&mut self, _: DiagInner) {
+                unimplemented!("false emitter must only used during `wrap_emitter`")
+            }
+
+            fn source_map(&self) -> Option<&Lrc<SourceMap>> {
+                unimplemented!("false emitter must only used during `wrap_emitter`")
+            }
         }
+
+        impl translation::Translate for FalseEmitter {
+            fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
+                unimplemented!("false emitter must only used during `wrap_emitter`")
+            }
+
+            fn fallback_fluent_bundle(&self) -> &FluentBundle {
+                unimplemented!("false emitter must only used during `wrap_emitter`")
+            }
+        }
+
+        let mut inner = self.inner.borrow_mut();
+        let mut prev_dcx = DiagCtxtInner::new(Box::new(FalseEmitter));
+        std::mem::swap(&mut *inner, &mut prev_dcx);
+        let new_emitter = f(prev_dcx);
+        let mut new_dcx = DiagCtxtInner::new(new_emitter);
+        std::mem::swap(&mut *inner, &mut new_dcx);
     }
 
     /// Translate `message` eagerly with `args` to `SubdiagMessage::Eager`.
@@ -1345,6 +1370,30 @@ impl DiagCtxt {
 // `DiagCtxt::foo()` just borrows `inner` and forwards a call to
 // `DiagCtxtInner::foo`.
 impl DiagCtxtInner {
+    fn new(emitter: Box<DynEmitter>) -> Self {
+        Self {
+            flags: DiagCtxtFlags { can_emit_warnings: true, ..Default::default() },
+            err_guars: Vec::new(),
+            lint_err_guars: Vec::new(),
+            delayed_bugs: Vec::new(),
+            deduplicated_err_count: 0,
+            deduplicated_warn_count: 0,
+            emitter,
+            must_produce_diag: false,
+            has_printed: false,
+            suppressed_expected_diag: false,
+            taught_diagnostics: Default::default(),
+            emitted_diagnostic_codes: Default::default(),
+            emitted_diagnostics: Default::default(),
+            stashed_diagnostics: Default::default(),
+            future_breakage_diagnostics: Vec::new(),
+            check_unstable_expect_diagnostics: false,
+            unstable_expect_diagnostics: Vec::new(),
+            fulfilled_expectations: Default::default(),
+            ice_file: None,
+        }
+    }
+
     /// Emit all stashed diagnostics.
     fn emit_stashed_diagnostics(&mut self) -> Option<ErrorGuaranteed> {
         let mut guar = None;
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index b6e2695590c13..2cc37651ef521 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -791,7 +791,12 @@ fn convert_enum_variant_types(tcx: TyCtxt<'_>, def_id: DefId) {
 }
 
 fn find_field(tcx: TyCtxt<'_>, (def_id, ident): (DefId, Ident)) -> Option<FieldIdx> {
-    tcx.adt_def(def_id).non_enum_variant().fields.iter_enumerated().find_map(|(idx, field)| {
+    let adt = tcx.adt_def(def_id);
+    if adt.is_enum() {
+        return None;
+    }
+
+    adt.non_enum_variant().fields.iter_enumerated().find_map(|(idx, field)| {
         if field.is_unnamed() {
             let field_ty = tcx.type_of(field.did).instantiate_identity();
             let adt_def = field_ty.ty_adt_def().expect("expect Adt for unnamed field");
diff --git a/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs b/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
index f0e998b7a0032..dcb01a117b047 100644
--- a/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
+++ b/compiler/rustc_hir_analysis/src/collect/type_of/opaque.rs
@@ -46,9 +46,7 @@ pub(super) fn find_opaque_ty_constraints_for_impl_trait_in_assoc_type(
     for &assoc_id in tcx.associated_item_def_ids(impl_def_id) {
         let assoc = tcx.associated_item(assoc_id);
         match assoc.kind {
-            ty::AssocKind::Const | ty::AssocKind::Fn => {
-                locator.check(assoc_id.expect_local(), ImplTraitSource::AssocTy)
-            }
+            ty::AssocKind::Const | ty::AssocKind::Fn => locator.check(assoc_id.expect_local()),
             // Associated types don't have bodies, so they can't constrain hidden types
             ty::AssocKind::Type => {}
         }
@@ -182,15 +180,9 @@ struct TaitConstraintLocator<'tcx> {
     typeck_types: Vec<ty::OpaqueHiddenType<'tcx>>,
 }
 
-#[derive(Debug)]
-enum ImplTraitSource {
-    AssocTy,
-    TyAlias,
-}
-
 impl TaitConstraintLocator<'_> {
     #[instrument(skip(self), level = "debug")]
-    fn check(&mut self, item_def_id: LocalDefId, source: ImplTraitSource) {
+    fn check(&mut self, item_def_id: LocalDefId) {
         // Don't try to check items that cannot possibly constrain the type.
         if !self.tcx.has_typeck_results(item_def_id) {
             debug!("no constraint: no typeck results");
@@ -242,12 +234,8 @@ impl TaitConstraintLocator<'_> {
                 continue;
             }
             constrained = true;
-            let opaque_types_defined_by = match source {
-                ImplTraitSource::AssocTy => {
-                    self.tcx.impl_trait_in_assoc_types_defined_by(item_def_id)
-                }
-                ImplTraitSource::TyAlias => self.tcx.opaque_types_defined_by(item_def_id),
-            };
+            let opaque_types_defined_by = self.tcx.opaque_types_defined_by(item_def_id);
+
             if !opaque_types_defined_by.contains(&self.def_id) {
                 self.tcx.dcx().emit_err(TaitForwardCompat {
                     span: hidden_type.span,
@@ -308,7 +296,7 @@ impl<'tcx> intravisit::Visitor<'tcx> for TaitConstraintLocator<'tcx> {
     }
     fn visit_expr(&mut self, ex: &'tcx Expr<'tcx>) {
         if let hir::ExprKind::Closure(closure) = ex.kind {
-            self.check(closure.def_id, ImplTraitSource::TyAlias);
+            self.check(closure.def_id);
         }
         intravisit::walk_expr(self, ex);
     }
@@ -316,7 +304,7 @@ impl<'tcx> intravisit::Visitor<'tcx> for TaitConstraintLocator<'tcx> {
         trace!(?it.owner_id);
         // The opaque type itself or its children are not within its reveal scope.
         if it.owner_id.def_id != self.def_id {
-            self.check(it.owner_id.def_id, ImplTraitSource::TyAlias);
+            self.check(it.owner_id.def_id);
             intravisit::walk_item(self, it);
         }
     }
@@ -324,13 +312,13 @@ impl<'tcx> intravisit::Visitor<'tcx> for TaitConstraintLocator<'tcx> {
         trace!(?it.owner_id);
         // The opaque type itself or its children are not within its reveal scope.
         if it.owner_id.def_id != self.def_id {
-            self.check(it.owner_id.def_id, ImplTraitSource::TyAlias);
+            self.check(it.owner_id.def_id);
             intravisit::walk_impl_item(self, it);
         }
     }
     fn visit_trait_item(&mut self, it: &'tcx TraitItem<'tcx>) {
         trace!(?it.owner_id);
-        self.check(it.owner_id.def_id, ImplTraitSource::TyAlias);
+        self.check(it.owner_id.def_id);
         intravisit::walk_trait_item(self, it);
     }
     fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem<'tcx>) {
diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index 3a2bbed19beff..b2ec8e5342924 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -45,9 +45,10 @@ pub struct Compiler {
 pub(crate) fn parse_cfg(dcx: &DiagCtxt, cfgs: Vec<String>) -> Cfg {
     cfgs.into_iter()
         .map(|s| {
-            let psess = ParseSess::with_silent_emitter(format!(
-                "this error occurred on the command line: `--cfg={s}`"
-            ));
+            let psess = ParseSess::with_silent_emitter(
+                vec![crate::DEFAULT_LOCALE_RESOURCE, rustc_parse::DEFAULT_LOCALE_RESOURCE],
+                format!("this error occurred on the command line: `--cfg={s}`"),
+            );
             let filename = FileName::cfg_spec_source_code(&s);
 
             macro_rules! error {
@@ -107,9 +108,10 @@ pub(crate) fn parse_check_cfg(dcx: &DiagCtxt, specs: Vec<String>) -> CheckCfg {
     let mut check_cfg = CheckCfg { exhaustive_names, exhaustive_values, ..CheckCfg::default() };
 
     for s in specs {
-        let psess = ParseSess::with_silent_emitter(format!(
-            "this error occurred on the command line: `--check-cfg={s}`"
-        ));
+        let psess = ParseSess::with_silent_emitter(
+            vec![crate::DEFAULT_LOCALE_RESOURCE, rustc_parse::DEFAULT_LOCALE_RESOURCE],
+            format!("this error occurred on the command line: `--check-cfg={s}`"),
+        );
         let filename = FileName::cfg_spec_source_code(&s);
 
         macro_rules! error {
diff --git a/compiler/rustc_lint/src/context/diagnostics.rs b/compiler/rustc_lint/src/context/diagnostics.rs
index a0aa252bcdf2f..a58a37bf3ac08 100644
--- a/compiler/rustc_lint/src/context/diagnostics.rs
+++ b/compiler/rustc_lint/src/context/diagnostics.rs
@@ -12,6 +12,43 @@ use rustc_span::edit_distance::find_best_match_for_name;
 use rustc_span::symbol::{sym, Symbol};
 use rustc_span::BytePos;
 
+const MAX_CHECK_CFG_NAMES_OR_VALUES: usize = 35;
+
+fn check_cfg_expected_note(
+    sess: &Session,
+    possibilities: &[Symbol],
+    type_: &str,
+    name: Option<Symbol>,
+    suffix: &str,
+) -> String {
+    use std::fmt::Write;
+
+    let n_possibilities = if sess.opts.unstable_opts.check_cfg_all_expected {
+        possibilities.len()
+    } else {
+        std::cmp::min(possibilities.len(), MAX_CHECK_CFG_NAMES_OR_VALUES)
+    };
+
+    let mut possibilities = possibilities.iter().map(Symbol::as_str).collect::<Vec<_>>();
+    possibilities.sort();
+
+    let and_more = possibilities.len().saturating_sub(n_possibilities);
+    let possibilities = possibilities[..n_possibilities].join("`, `");
+
+    let mut note = String::with_capacity(50 + possibilities.len());
+
+    write!(&mut note, "expected {type_}").unwrap();
+    if let Some(name) = name {
+        write!(&mut note, " for `{name}`").unwrap();
+    }
+    write!(&mut note, " are: {suffix}`{possibilities}`").unwrap();
+    if and_more > 0 {
+        write!(&mut note, " and {and_more} more").unwrap();
+    }
+
+    note
+}
+
 pub(super) fn builtin(sess: &Session, diagnostic: BuiltinLintDiag, diag: &mut Diag<'_, ()>) {
     match diagnostic {
         BuiltinLintDiag::UnicodeTextFlow(span, content) => {
@@ -286,16 +323,13 @@ pub(super) fn builtin(sess: &Session, diagnostic: BuiltinLintDiag, diag: &mut Di
                     }
                 }
                 if !possibilities.is_empty() {
-                    let mut possibilities =
-                        possibilities.iter().map(Symbol::as_str).collect::<Vec<_>>();
-                    possibilities.sort();
-                    let possibilities = possibilities.join("`, `");
-
-                    // The list of expected names can be long (even by default) and
-                    // so the diagnostic produced can take a lot of space. To avoid
-                    // cloging the user output we only want to print that diagnostic
-                    // once.
-                    diag.help_once(format!("expected names are: `{possibilities}`"));
+                    diag.help_once(check_cfg_expected_note(
+                        sess,
+                        &possibilities,
+                        "names",
+                        None,
+                        "",
+                    ));
                 }
             }
 
@@ -338,16 +372,13 @@ pub(super) fn builtin(sess: &Session, diagnostic: BuiltinLintDiag, diag: &mut Di
             // Show the full list if all possible values for a given name, but don't do it
             // for names as the possibilities could be very long
             if !possibilities.is_empty() {
-                {
-                    let mut possibilities =
-                        possibilities.iter().map(Symbol::as_str).collect::<Vec<_>>();
-                    possibilities.sort();
-
-                    let possibilities = possibilities.join("`, `");
-                    let none = if have_none_possibility { "(none), " } else { "" };
-
-                    diag.note(format!("expected values for `{name}` are: {none}`{possibilities}`"));
-                }
+                diag.note(check_cfg_expected_note(
+                    sess,
+                    &possibilities,
+                    "values",
+                    Some(name),
+                    if have_none_possibility { "(none), " } else { "" },
+                ));
 
                 if let Some((value, value_span)) = value {
                     // Suggest the most probable if we found one
diff --git a/compiler/rustc_lint/src/types.rs b/compiler/rustc_lint/src/types.rs
index 71f330b5bf799..65efec73aa8b5 100644
--- a/compiler/rustc_lint/src/types.rs
+++ b/compiler/rustc_lint/src/types.rs
@@ -984,7 +984,14 @@ pub fn transparent_newtype_field<'a, 'tcx>(
 }
 
 /// Is type known to be non-null?
-fn ty_is_known_nonnull<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, mode: CItemKind) -> bool {
+fn ty_is_known_nonnull<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+    ty: Ty<'tcx>,
+    mode: CItemKind,
+) -> bool {
+    let ty = tcx.try_normalize_erasing_regions(param_env, ty).unwrap_or(ty);
+
     match ty.kind() {
         ty::FnPtr(_) => true,
         ty::Ref(..) => true,
@@ -1004,7 +1011,7 @@ fn ty_is_known_nonnull<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, mode: CItemKind) -
             def.variants()
                 .iter()
                 .filter_map(|variant| transparent_newtype_field(tcx, variant))
-                .any(|field| ty_is_known_nonnull(tcx, field.ty(tcx, args), mode))
+                .any(|field| ty_is_known_nonnull(tcx, param_env, field.ty(tcx, args), mode))
         }
         _ => false,
     }
@@ -1012,7 +1019,13 @@ fn ty_is_known_nonnull<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, mode: CItemKind) -
 
 /// Given a non-null scalar (or transparent) type `ty`, return the nullable version of that type.
 /// If the type passed in was not scalar, returns None.
-fn get_nullable_type<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
+fn get_nullable_type<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    param_env: ty::ParamEnv<'tcx>,
+    ty: Ty<'tcx>,
+) -> Option<Ty<'tcx>> {
+    let ty = tcx.try_normalize_erasing_regions(param_env, ty).unwrap_or(ty);
+
     Some(match *ty.kind() {
         ty::Adt(field_def, field_args) => {
             let inner_field_ty = {
@@ -1028,22 +1041,19 @@ fn get_nullable_type<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>>
                     .expect("No non-zst fields in transparent type.")
                     .ty(tcx, field_args)
             };
-            return get_nullable_type(tcx, inner_field_ty);
+            return get_nullable_type(tcx, param_env, inner_field_ty);
         }
         ty::Int(ty) => Ty::new_int(tcx, ty),
         ty::Uint(ty) => Ty::new_uint(tcx, ty),
         ty::RawPtr(ty_mut) => Ty::new_ptr(tcx, ty_mut),
         // As these types are always non-null, the nullable equivalent of
-        // Option<T> of these types are their raw pointer counterparts.
+        // `Option<T>` of these types are their raw pointer counterparts.
         ty::Ref(_region, ty, mutbl) => Ty::new_ptr(tcx, ty::TypeAndMut { ty, mutbl }),
-        ty::FnPtr(..) => {
-            // There is no nullable equivalent for Rust's function pointers -- you
-            // must use an Option<fn(..) -> _> to represent it.
-            ty
-        }
-
-        // We should only ever reach this case if ty_is_known_nonnull is extended
-        // to other types.
+        // There is no nullable equivalent for Rust's function pointers,
+        // you must use an `Option<fn(..) -> _>` to represent it.
+        ty::FnPtr(..) => ty,
+        // We should only ever reach this case if `ty_is_known_nonnull` is
+        // extended to other types.
         ref unhandled => {
             debug!(
                 "get_nullable_type: Unhandled scalar kind: {:?} while checking {:?}",
@@ -1056,7 +1066,7 @@ fn get_nullable_type<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>>
 
 /// Check if this enum can be safely exported based on the "nullable pointer optimization". If it
 /// can, return the type that `ty` can be safely converted to, otherwise return `None`.
-/// Currently restricted to function pointers, boxes, references, `core::num::NonZero*`,
+/// Currently restricted to function pointers, boxes, references, `core::num::NonZero`,
 /// `core::ptr::NonNull`, and `#[repr(transparent)]` newtypes.
 /// FIXME: This duplicates code in codegen.
 pub(crate) fn repr_nullable_ptr<'tcx>(
@@ -1075,7 +1085,7 @@ pub(crate) fn repr_nullable_ptr<'tcx>(
             _ => return None,
         };
 
-        if !ty_is_known_nonnull(tcx, field_ty, ckind) {
+        if !ty_is_known_nonnull(tcx, param_env, field_ty, ckind) {
             return None;
         }
 
@@ -1099,10 +1109,10 @@ pub(crate) fn repr_nullable_ptr<'tcx>(
                 WrappingRange { start: 0, end }
                     if end == field_ty_scalar.size(&tcx).unsigned_int_max() - 1 =>
                 {
-                    return Some(get_nullable_type(tcx, field_ty).unwrap());
+                    return Some(get_nullable_type(tcx, param_env, field_ty).unwrap());
                 }
                 WrappingRange { start: 1, .. } => {
-                    return Some(get_nullable_type(tcx, field_ty).unwrap());
+                    return Some(get_nullable_type(tcx, param_env, field_ty).unwrap());
                 }
                 WrappingRange { start, end } => {
                     unreachable!("Unhandled start and end range: ({}, {})", start, end)
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 8b48570fbbadd..0d37c0feb0c24 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -1132,7 +1132,13 @@ fn load_dylib(path: &Path, max_attempts: usize) -> Result<libloading::Library, S
             Err(err) => {
                 // Only try to recover from this specific error.
                 if !matches!(err, libloading::Error::LoadLibraryExW { .. }) {
-                    return Err(err.to_string());
+                    let err = format_dlopen_err(&err);
+                    // We include the path of the dylib in the error ourselves, so
+                    // if it's in the error, we strip it.
+                    if let Some(err) = err.strip_prefix(&format!(": {}", path.display())) {
+                        return Err(err.to_string());
+                    }
+                    return Err(err);
                 }
 
                 last_error = Some(err);
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 8357c21a3c2be..b0431ae05d395 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -344,15 +344,6 @@ rustc_queries! {
         }
     }
 
-    query impl_trait_in_assoc_types_defined_by(
-        key: LocalDefId
-    ) -> &'tcx ty::List<LocalDefId> {
-        desc {
-            |tcx| "computing the opaque types defined by `{}`",
-            tcx.def_path_str(key.to_def_id())
-        }
-    }
-
     /// Returns the list of bounds that can be used for
     /// `SelectionCandidate::ProjectionCandidate(_)` and
     /// `ProjectionTyCandidate::TraitDef`.
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 0cd925c5ba6ae..6647a9a279285 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -8,8 +8,8 @@ use crate::errors::{
     ItemsInTraitsAreNotImportable,
 };
 use crate::Determinacy::{self, *};
-use crate::Namespace::*;
 use crate::{module_to_string, names_to_string, ImportSuggestion};
+use crate::{AmbiguityError, Namespace::*};
 use crate::{AmbiguityKind, BindingKey, ResolutionError, Resolver, Segment};
 use crate::{Finalize, Module, ModuleOrUniformRoot, ParentScope, PerNS, ScopeSet};
 use crate::{NameBinding, NameBindingData, NameBindingKind, PathResult, Used};
@@ -538,7 +538,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             .chain(indeterminate_imports.iter().map(|i| (true, i)))
         {
             let unresolved_import_error = self.finalize_import(*import);
-
             // If this import is unresolved then create a dummy import
             // resolution for it so that later resolve stages won't complain.
             self.import_dummy_binding(*import, is_indeterminate);
@@ -856,7 +855,9 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             ImportKind::Single { target_bindings, .. } => target_bindings[TypeNS].get(),
             _ => None,
         };
-        let prev_ambiguity_errors_len = self.ambiguity_errors.len();
+        let ambiguity_errors_len =
+            |errors: &Vec<AmbiguityError<'_>>| errors.iter().filter(|error| !error.warning).count();
+        let prev_ambiguity_errors_len = ambiguity_errors_len(&self.ambiguity_errors);
         let finalize = Finalize::with_root_span(import.root_id, import.span, import.root_span);
 
         // We'll provide more context to the privacy errors later, up to `len`.
@@ -870,7 +871,8 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             ignore_binding,
         );
 
-        let no_ambiguity = self.ambiguity_errors.len() == prev_ambiguity_errors_len;
+        let no_ambiguity =
+            ambiguity_errors_len(&self.ambiguity_errors) == prev_ambiguity_errors_len;
         import.vis.set(orig_vis);
         let module = match path_res {
             PathResult::Module(module) => {
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 42c9d5e10eba1..55e1556cdf8d6 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1565,6 +1565,8 @@ options! {
         "set options for branch target identification and pointer authentication on AArch64"),
     cf_protection: CFProtection = (CFProtection::None, parse_cfprotection, [TRACKED],
         "instrument control-flow architecture protection"),
+    check_cfg_all_expected: bool = (false, parse_bool, [UNTRACKED],
+        "show all expected values in check-cfg diagnostics (default: no)"),
     codegen_backend: Option<String> = (None, parse_opt_string, [TRACKED],
         "the backend to use"),
     collapse_macro_debuginfo: CollapseMacroDebuginfo = (CollapseMacroDebuginfo::Unspecified,
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index 25b5422f3225f..506bd5d5dbd81 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -265,14 +265,20 @@ impl ParseSess {
         }
     }
 
-    pub fn with_silent_emitter(fatal_note: String) -> Self {
-        let fallback_bundle = fallback_fluent_bundle(Vec::new(), false);
+    pub fn with_silent_emitter(locale_resources: Vec<&'static str>, fatal_note: String) -> Self {
+        let fallback_bundle = fallback_fluent_bundle(locale_resources, false);
         let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
-        let emitter =
-            Box::new(HumanEmitter::new(stderr_destination(ColorConfig::Auto), fallback_bundle));
+        let emitter = Box::new(HumanEmitter::new(
+            stderr_destination(ColorConfig::Auto),
+            fallback_bundle.clone(),
+        ));
         let fatal_dcx = DiagCtxt::new(emitter);
-        let dcx =
-            DiagCtxt::new(Box::new(SilentEmitter { fatal_dcx, fatal_note })).disable_warnings();
+        let dcx = DiagCtxt::new(Box::new(SilentEmitter {
+            fallback_bundle,
+            fatal_dcx,
+            fatal_note: Some(fatal_note),
+        }))
+        .disable_warnings();
         ParseSess::with_dcx(dcx, sm)
     }
 
diff --git a/compiler/rustc_ty_utils/src/opaque_types.rs b/compiler/rustc_ty_utils/src/opaque_types.rs
index 282595169737d..0ac14b338ac12 100644
--- a/compiler/rustc_ty_utils/src/opaque_types.rs
+++ b/compiler/rustc_ty_utils/src/opaque_types.rs
@@ -34,7 +34,11 @@ enum CollectionMode {
 }
 
 impl<'tcx> OpaqueTypeCollector<'tcx> {
-    fn new(tcx: TyCtxt<'tcx>, item: LocalDefId, mode: CollectionMode) -> Self {
+    fn new(tcx: TyCtxt<'tcx>, item: LocalDefId) -> Self {
+        let mode = match tcx.def_kind(tcx.local_parent(item)) {
+            DefKind::Impl { of_trait: true } => CollectionMode::ImplTraitInAssocTypes,
+            _ => CollectionMode::TypeAliasImplTraitTransition,
+        };
         Self { tcx, opaques: Vec::new(), item, seen: Default::default(), span: None, mode }
     }
 
@@ -287,23 +291,13 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for OpaqueTypeCollector<'tcx> {
     }
 }
 
-fn impl_trait_in_assoc_types_defined_by<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    item: LocalDefId,
-) -> &'tcx ty::List<LocalDefId> {
-    let mut collector = OpaqueTypeCollector::new(tcx, item, CollectionMode::ImplTraitInAssocTypes);
-    super::sig_types::walk_types(tcx, item, &mut collector);
-    tcx.mk_local_def_ids(&collector.opaques)
-}
-
 fn opaque_types_defined_by<'tcx>(
     tcx: TyCtxt<'tcx>,
     item: LocalDefId,
 ) -> &'tcx ty::List<LocalDefId> {
     let kind = tcx.def_kind(item);
     trace!(?kind);
-    let mut collector =
-        OpaqueTypeCollector::new(tcx, item, CollectionMode::TypeAliasImplTraitTransition);
+    let mut collector = OpaqueTypeCollector::new(tcx, item);
     super::sig_types::walk_types(tcx, item, &mut collector);
     match kind {
         DefKind::AssocFn
@@ -346,6 +340,5 @@ fn opaque_types_defined_by<'tcx>(
 }
 
 pub(super) fn provide(providers: &mut Providers) {
-    *providers =
-        Providers { opaque_types_defined_by, impl_trait_in_assoc_types_defined_by, ..*providers };
+    *providers = Providers { opaque_types_defined_by, ..*providers };
 }
diff --git a/library/core/src/num/nonzero.rs b/library/core/src/num/nonzero.rs
index 9e34c0d240dc2..5605c871281b8 100644
--- a/library/core/src/num/nonzero.rs
+++ b/library/core/src/num/nonzero.rs
@@ -6,21 +6,13 @@ use crate::hash::{Hash, Hasher};
 use crate::intrinsics;
 use crate::marker::StructuralPartialEq;
 use crate::ops::{BitOr, BitOrAssign, Div, Neg, Rem};
+use crate::panic::{RefUnwindSafe, UnwindSafe};
+use crate::ptr;
 use crate::str::FromStr;
 
 use super::from_str_radix;
 use super::{IntErrorKind, ParseIntError};
 
-mod private {
-    #[unstable(
-        feature = "nonzero_internals",
-        reason = "implementation detail which may disappear or be replaced at any time",
-        issue = "none"
-    )]
-    #[const_trait]
-    pub trait Sealed {}
-}
-
 /// A marker trait for primitive types which can be zero.
 ///
 /// This is an implementation detail for <code>[NonZero]\<T></code> which may disappear or be replaced at any time.
@@ -34,38 +26,70 @@ mod private {
     issue = "none"
 )]
 #[const_trait]
-pub unsafe trait ZeroablePrimitive: Sized + Copy + private::Sealed {}
+pub unsafe trait ZeroablePrimitive: Sized + Copy + private::Sealed {
+    #[doc(hidden)]
+    type NonZeroInner: Sized + Copy;
+}
 
 macro_rules! impl_zeroable_primitive {
-    ($primitive:ty) => {
-        #[unstable(
-            feature = "nonzero_internals",
-            reason = "implementation detail which may disappear or be replaced at any time",
-            issue = "none"
-        )]
-        impl const private::Sealed for $primitive {}
-
-        #[unstable(
-            feature = "nonzero_internals",
-            reason = "implementation detail which may disappear or be replaced at any time",
-            issue = "none"
-        )]
-        unsafe impl const ZeroablePrimitive for $primitive {}
+    ($($NonZeroInner:ident ( $primitive:ty )),+ $(,)?) => {
+        mod private {
+            #[unstable(
+                feature = "nonzero_internals",
+                reason = "implementation detail which may disappear or be replaced at any time",
+                issue = "none"
+            )]
+            #[const_trait]
+            pub trait Sealed {}
+
+            $(
+                #[derive(Debug, Clone, Copy, PartialEq)]
+                #[repr(transparent)]
+                #[rustc_layout_scalar_valid_range_start(1)]
+                #[rustc_nonnull_optimization_guaranteed]
+                #[unstable(
+                    feature = "nonzero_internals",
+                    reason = "implementation detail which may disappear or be replaced at any time",
+                    issue = "none"
+                )]
+                pub struct $NonZeroInner($primitive);
+            )+
+        }
+
+        $(
+            #[unstable(
+                feature = "nonzero_internals",
+                reason = "implementation detail which may disappear or be replaced at any time",
+                issue = "none"
+            )]
+            impl const private::Sealed for $primitive {}
+
+            #[unstable(
+                feature = "nonzero_internals",
+                reason = "implementation detail which may disappear or be replaced at any time",
+                issue = "none"
+            )]
+            unsafe impl const ZeroablePrimitive for $primitive {
+                type NonZeroInner = private::$NonZeroInner;
+            }
+        )+
     };
 }
 
-impl_zeroable_primitive!(u8);
-impl_zeroable_primitive!(u16);
-impl_zeroable_primitive!(u32);
-impl_zeroable_primitive!(u64);
-impl_zeroable_primitive!(u128);
-impl_zeroable_primitive!(usize);
-impl_zeroable_primitive!(i8);
-impl_zeroable_primitive!(i16);
-impl_zeroable_primitive!(i32);
-impl_zeroable_primitive!(i64);
-impl_zeroable_primitive!(i128);
-impl_zeroable_primitive!(isize);
+impl_zeroable_primitive!(
+    NonZeroU8Inner(u8),
+    NonZeroU16Inner(u16),
+    NonZeroU32Inner(u32),
+    NonZeroU64Inner(u64),
+    NonZeroU128Inner(u128),
+    NonZeroUsizeInner(usize),
+    NonZeroI8Inner(i8),
+    NonZeroI16Inner(i16),
+    NonZeroI32Inner(i32),
+    NonZeroI64Inner(i64),
+    NonZeroI128Inner(i128),
+    NonZeroIsizeInner(isize),
+);
 
 /// A value that is known not to equal zero.
 ///
@@ -80,10 +104,9 @@ impl_zeroable_primitive!(isize);
 /// ```
 #[unstable(feature = "generic_nonzero", issue = "120257")]
 #[repr(transparent)]
-#[rustc_layout_scalar_valid_range_start(1)]
 #[rustc_nonnull_optimization_guaranteed]
 #[rustc_diagnostic_item = "NonZero"]
-pub struct NonZero<T: ZeroablePrimitive>(T);
+pub struct NonZero<T: ZeroablePrimitive>(T::NonZeroInner);
 
 macro_rules! impl_nonzero_fmt {
     ($Trait:ident) => {
@@ -107,6 +130,25 @@ impl_nonzero_fmt!(Octal);
 impl_nonzero_fmt!(LowerHex);
 impl_nonzero_fmt!(UpperHex);
 
+macro_rules! impl_nonzero_auto_trait {
+    (unsafe $Trait:ident) => {
+        #[stable(feature = "nonzero", since = "1.28.0")]
+        unsafe impl<T> $Trait for NonZero<T> where T: ZeroablePrimitive + $Trait {}
+    };
+    ($Trait:ident) => {
+        #[stable(feature = "nonzero", since = "1.28.0")]
+        impl<T> $Trait for NonZero<T> where T: ZeroablePrimitive + $Trait {}
+    };
+}
+
+// Implement auto-traits manually based on `T` to avoid docs exposing
+// the `ZeroablePrimitive::NonZeroInner` implementation detail.
+impl_nonzero_auto_trait!(RefUnwindSafe);
+impl_nonzero_auto_trait!(unsafe Send);
+impl_nonzero_auto_trait!(unsafe Sync);
+impl_nonzero_auto_trait!(Unpin);
+impl_nonzero_auto_trait!(UnwindSafe);
+
 #[stable(feature = "nonzero", since = "1.28.0")]
 impl<T> Clone for NonZero<T>
 where
@@ -114,8 +156,7 @@ where
 {
     #[inline]
     fn clone(&self) -> Self {
-        // SAFETY: The contained value is non-zero.
-        unsafe { Self(self.0) }
+        Self(self.0)
     }
 }
 
@@ -188,19 +229,19 @@ where
     #[inline]
     fn max(self, other: Self) -> Self {
         // SAFETY: The maximum of two non-zero values is still non-zero.
-        unsafe { Self(self.get().max(other.get())) }
+        unsafe { Self::new_unchecked(self.get().max(other.get())) }
     }
 
     #[inline]
     fn min(self, other: Self) -> Self {
         // SAFETY: The minimum of two non-zero values is still non-zero.
-        unsafe { Self(self.get().min(other.get())) }
+        unsafe { Self::new_unchecked(self.get().min(other.get())) }
     }
 
     #[inline]
     fn clamp(self, min: Self, max: Self) -> Self {
         // SAFETY: A non-zero value clamped between two non-zero values is still non-zero.
-        unsafe { Self(self.get().clamp(min.get(), max.get())) }
+        unsafe { Self::new_unchecked(self.get().clamp(min.get(), max.get())) }
     }
 }
 
@@ -240,7 +281,7 @@ where
     #[inline]
     fn bitor(self, rhs: Self) -> Self::Output {
         // SAFETY: Bitwise OR of two non-zero values is still non-zero.
-        unsafe { Self(self.get() | rhs.get()) }
+        unsafe { Self::new_unchecked(self.get() | rhs.get()) }
     }
 }
 
@@ -254,7 +295,7 @@ where
     #[inline]
     fn bitor(self, rhs: T) -> Self::Output {
         // SAFETY: Bitwise OR of a non-zero value with anything is still non-zero.
-        unsafe { Self(self.get() | rhs) }
+        unsafe { Self::new_unchecked(self.get() | rhs) }
     }
 }
 
@@ -268,7 +309,7 @@ where
     #[inline]
     fn bitor(self, rhs: NonZero<T>) -> Self::Output {
         // SAFETY: Bitwise OR of anything with a non-zero value is still non-zero.
-        unsafe { NonZero(self | rhs.get()) }
+        unsafe { NonZero::new_unchecked(self | rhs.get()) }
     }
 }
 
@@ -345,7 +386,7 @@ where
     pub fn from_mut(n: &mut T) -> Option<&mut Self> {
         // SAFETY: Memory layout optimization guarantees that `Option<NonZero<T>>` has
         //         the same layout and size as `T`, with `0` representing `None`.
-        let opt_n = unsafe { &mut *(n as *mut T as *mut Option<Self>) };
+        let opt_n = unsafe { &mut *(ptr::from_mut(n).cast::<Option<Self>>()) };
 
         opt_n.as_mut()
     }
@@ -388,12 +429,17 @@ where
         // memory somewhere. If the value of `self` was from by-value argument
         // of some not-inlined function, LLVM don't have range metadata
         // to understand that the value cannot be zero.
-        match Self::new(self.0) {
-            Some(Self(n)) => n,
+        //
+        // SAFETY: `Self` is guaranteed to have the same layout as `Option<Self>`.
+        match unsafe { intrinsics::transmute_unchecked(self) } {
             None => {
                 // SAFETY: `NonZero` is guaranteed to only contain non-zero values, so this is unreachable.
                 unsafe { intrinsics::unreachable() }
             }
+            Some(Self(inner)) => {
+                // SAFETY: `T::NonZeroInner` is guaranteed to have the same layout as `T`.
+                unsafe { intrinsics::transmute_unchecked(inner) }
+            }
         }
     }
 }
diff --git a/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_callee_ret.stderr b/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_callee_ret.stderr
index 7d481940acec9..35de453522257 100644
--- a/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_callee_ret.stderr
+++ b/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_callee_ret.stderr
@@ -1,8 +1,8 @@
-error: Undefined Behavior: constructing invalid value: encountered 0, but expected something greater or equal to 1
+error: Undefined Behavior: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
   --> $DIR/cast_fn_ptr_invalid_callee_ret.rs:LL:CC
    |
 LL |     f();
-   |     ^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   |     ^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
diff --git a/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_caller_arg.stderr b/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_caller_arg.stderr
index b1a2bd2c79a40..81d775f6d7f5f 100644
--- a/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_caller_arg.stderr
+++ b/src/tools/miri/tests/fail/validity/cast_fn_ptr_invalid_caller_arg.stderr
@@ -1,8 +1,8 @@
-error: Undefined Behavior: constructing invalid value: encountered 0, but expected something greater or equal to 1
+error: Undefined Behavior: constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
   --> $DIR/cast_fn_ptr_invalid_caller_arg.rs:LL:CC
    |
 LL |             Call(_res = f(*ptr), ReturnTo(retblock), UnwindContinue())
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information
diff --git a/src/tools/rustfmt/src/parse/session.rs b/src/tools/rustfmt/src/parse/session.rs
index 11af986051351..60a89a5753641 100644
--- a/src/tools/rustfmt/src/parse/session.rs
+++ b/src/tools/rustfmt/src/parse/session.rs
@@ -1,9 +1,8 @@
-use std::borrow::Cow;
 use std::path::Path;
 use std::sync::atomic::{AtomicBool, Ordering};
 
 use rustc_data_structures::sync::{IntoDynSyncSend, Lrc};
-use rustc_errors::emitter::{stderr_destination, DynEmitter, Emitter, HumanEmitter};
+use rustc_errors::emitter::{stderr_destination, DynEmitter, Emitter, HumanEmitter, SilentEmitter};
 use rustc_errors::translation::Translate;
 use rustc_errors::{ColorConfig, Diag, DiagCtxt, DiagInner, Level as DiagnosticLevel};
 use rustc_session::parse::ParseSess as RawParseSess;
@@ -28,41 +27,6 @@ pub(crate) struct ParseSess {
     can_reset_errors: Lrc<AtomicBool>,
 }
 
-/// Emitter which discards every error.
-struct SilentEmitter;
-
-impl Translate for SilentEmitter {
-    fn fluent_bundle(&self) -> Option<&Lrc<rustc_errors::FluentBundle>> {
-        None
-    }
-
-    fn fallback_fluent_bundle(&self) -> &rustc_errors::FluentBundle {
-        panic!("silent emitter attempted to translate a diagnostic");
-    }
-
-    // Override `translate_message` for the silent emitter because eager translation of
-    // subdiagnostics result in a call to this.
-    fn translate_message<'a>(
-        &'a self,
-        message: &'a rustc_errors::DiagMessage,
-        _: &'a rustc_errors::translation::FluentArgs<'_>,
-    ) -> Result<Cow<'_, str>, rustc_errors::error::TranslateError<'_>> {
-        rustc_errors::emitter::silent_translate(message)
-    }
-}
-
-impl Emitter for SilentEmitter {
-    fn source_map(&self) -> Option<&Lrc<SourceMap>> {
-        None
-    }
-
-    fn emit_diagnostic(&mut self, _diag: DiagInner) {}
-}
-
-fn silent_emitter() -> Box<DynEmitter> {
-    Box::new(SilentEmitter {})
-}
-
 /// Emit errors against every files expect ones specified in the `ignore_path_set`.
 struct SilentOnIgnoredFilesEmitter {
     ignore_path_set: IntoDynSyncSend<Lrc<IgnorePathSet>>,
@@ -143,17 +107,23 @@ fn default_dcx(
         ColorConfig::Never
     };
 
-    let emitter = if hide_parse_errors {
-        silent_emitter()
+    let fallback_bundle = rustc_errors::fallback_fluent_bundle(
+        rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(),
+        false,
+    );
+    let emitter = Box::new(
+        HumanEmitter::new(stderr_destination(emit_color), fallback_bundle.clone())
+            .sm(Some(source_map.clone())),
+    );
+
+    let emitter: Box<DynEmitter> = if hide_parse_errors {
+        Box::new(SilentEmitter {
+            fallback_bundle,
+            fatal_dcx: DiagCtxt::new(emitter),
+            fatal_note: None,
+        })
     } else {
-        let fallback_bundle = rustc_errors::fallback_fluent_bundle(
-            rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(),
-            false,
-        );
-        Box::new(
-            HumanEmitter::new(stderr_destination(emit_color), fallback_bundle)
-                .sm(Some(source_map.clone())),
-        )
+        emitter
     };
     DiagCtxt::new(Box::new(SilentOnIgnoredFilesEmitter {
         has_non_ignorable_parser_errors: false,
@@ -232,7 +202,14 @@ impl ParseSess {
     }
 
     pub(crate) fn set_silent_emitter(&mut self) {
-        self.raw_psess.dcx = DiagCtxt::new(silent_emitter());
+        // Ideally this invocation wouldn't be necessary and the fallback bundle in
+        // `self.parse_sess.dcx` could be used, but the lock in `DiagCtxt` prevents this.
+        // See `<rustc_errors::SilentEmitter as Translate>::fallback_fluent_bundle`.
+        let fallback_bundle = rustc_errors::fallback_fluent_bundle(
+            rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(),
+            false,
+        );
+        self.raw_psess.dcx.make_silent(fallback_bundle, None);
     }
 
     pub(crate) fn span_to_filename(&self, span: Span) -> FileName {
diff --git a/src/tools/rustfmt/tests/rustfmt/main.rs b/src/tools/rustfmt/tests/rustfmt/main.rs
index 7dcf7c8416eec..e66fad1e7fa7b 100644
--- a/src/tools/rustfmt/tests/rustfmt/main.rs
+++ b/src/tools/rustfmt/tests/rustfmt/main.rs
@@ -176,7 +176,7 @@ fn rustfmt_emits_error_on_line_overflow_true() {
 #[test]
 #[allow(non_snake_case)]
 fn dont_emit_ICE() {
-    let files = ["tests/target/issue_5728.rs", "tests/target/issue_5729.rs"];
+    let files = ["tests/target/issue_5728.rs", "tests/target/issue_5729.rs", "tests/target/issue_6082.rs"];
 
     for file in files {
         let args = [file];
diff --git a/src/tools/rustfmt/tests/target/issue_6082.rs b/src/tools/rustfmt/tests/target/issue_6082.rs
new file mode 100644
index 0000000000000..58e512c710e98
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/issue_6082.rs
@@ -0,0 +1,5 @@
+macro_rules! test {
+    ($T:ident, $b:lifetime) => {
+        Box<$T<$b>>
+    };
+}
diff --git a/tests/ui/check-cfg/mix.rs b/tests/ui/check-cfg/mix.rs
index ba30bc1e69b50..69156ab67635e 100644
--- a/tests/ui/check-cfg/mix.rs
+++ b/tests/ui/check-cfg/mix.rs
@@ -74,6 +74,8 @@ fn test_cfg_macro() {
     //~^ WARNING unexpected `cfg` condition value
     //~| WARNING unexpected `cfg` condition value
     //~| WARNING unexpected `cfg` condition value
+    cfg!(target_feature = "zebra");
+    //~^ WARNING unexpected `cfg` condition value
 }
 
 fn main() {}
diff --git a/tests/ui/check-cfg/mix.stderr b/tests/ui/check-cfg/mix.stderr
index 77643f227d9d0..93333e5ef2a5b 100644
--- a/tests/ui/check-cfg/mix.stderr
+++ b/tests/ui/check-cfg/mix.stderr
@@ -245,5 +245,14 @@ LL |     cfg!(all(feature = "zebra", feature = "zebra", feature = "zebra"));
    = help: to expect this configuration use `--check-cfg=cfg(feature, values("zebra"))`
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
-warning: 26 warnings emitted
+warning: unexpected `cfg` condition value: `zebra`
+  --> $DIR/mix.rs:77:10
+   |
+LL |     cfg!(target_feature = "zebra");
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: expected values for `target_feature` are: `10e60`, `2e3`, `3e3r1`, `3e3r2`, `3e3r3`, `3e7`, `7e10`, `a`, `aclass`, `adx`, `aes`, `altivec`, `alu32`, `atomics`, `avx`, `avx2`, `avx512bf16`, `avx512bitalg`, `avx512bw`, `avx512cd`, `avx512dq`, `avx512er`, `avx512f`, `avx512fp16`, `avx512ifma`, `avx512pf`, `avx512vbmi`, `avx512vbmi2`, `avx512vl`, `avx512vnni`, `avx512vp2intersect`, `avx512vpopcntdq`, `bf16`, `bmi1`, `bmi2` and 186 more
+   = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
+
+warning: 27 warnings emitted
 
diff --git a/tests/ui/check-cfg/well-known-values.rs b/tests/ui/check-cfg/well-known-values.rs
index 859a36c604c6f..fa062a3fe2eae 100644
--- a/tests/ui/check-cfg/well-known-values.rs
+++ b/tests/ui/check-cfg/well-known-values.rs
@@ -6,6 +6,7 @@
 //
 //@ check-pass
 //@ compile-flags: --check-cfg=cfg() -Z unstable-options
+//@ compile-flags: -Zcheck-cfg-all-expected
 
 #![feature(cfg_overflow_checks)]
 #![feature(cfg_relocation_model)]
diff --git a/tests/ui/check-cfg/well-known-values.stderr b/tests/ui/check-cfg/well-known-values.stderr
index 01fc3f83f162b..86df829fe726c 100644
--- a/tests/ui/check-cfg/well-known-values.stderr
+++ b/tests/ui/check-cfg/well-known-values.stderr
@@ -1,5 +1,5 @@
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:25:5
+  --> $DIR/well-known-values.rs:26:5
    |
 LL |     clippy = "_UNEXPECTED_VALUE",
    |     ^^^^^^----------------------
@@ -11,7 +11,7 @@ LL |     clippy = "_UNEXPECTED_VALUE",
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:27:5
+  --> $DIR/well-known-values.rs:28:5
    |
 LL |     debug_assertions = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^----------------------
@@ -22,7 +22,7 @@ LL |     debug_assertions = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:29:5
+  --> $DIR/well-known-values.rs:30:5
    |
 LL |     doc = "_UNEXPECTED_VALUE",
    |     ^^^----------------------
@@ -33,7 +33,7 @@ LL |     doc = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:31:5
+  --> $DIR/well-known-values.rs:32:5
    |
 LL |     doctest = "_UNEXPECTED_VALUE",
    |     ^^^^^^^----------------------
@@ -44,7 +44,7 @@ LL |     doctest = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:33:5
+  --> $DIR/well-known-values.rs:34:5
    |
 LL |     miri = "_UNEXPECTED_VALUE",
    |     ^^^^----------------------
@@ -55,7 +55,7 @@ LL |     miri = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:35:5
+  --> $DIR/well-known-values.rs:36:5
    |
 LL |     overflow_checks = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^----------------------
@@ -66,7 +66,7 @@ LL |     overflow_checks = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:37:5
+  --> $DIR/well-known-values.rs:38:5
    |
 LL |     panic = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -75,7 +75,7 @@ LL |     panic = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:39:5
+  --> $DIR/well-known-values.rs:40:5
    |
 LL |     proc_macro = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^----------------------
@@ -86,7 +86,7 @@ LL |     proc_macro = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:41:5
+  --> $DIR/well-known-values.rs:42:5
    |
 LL |     relocation_model = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -95,7 +95,7 @@ LL |     relocation_model = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:43:5
+  --> $DIR/well-known-values.rs:44:5
    |
 LL |     sanitize = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -104,7 +104,7 @@ LL |     sanitize = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:45:5
+  --> $DIR/well-known-values.rs:46:5
    |
 LL |     target_abi = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -113,7 +113,7 @@ LL |     target_abi = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:47:5
+  --> $DIR/well-known-values.rs:48:5
    |
 LL |     target_arch = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -122,7 +122,7 @@ LL |     target_arch = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:49:5
+  --> $DIR/well-known-values.rs:50:5
    |
 LL |     target_endian = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -131,7 +131,7 @@ LL |     target_endian = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:51:5
+  --> $DIR/well-known-values.rs:52:5
    |
 LL |     target_env = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -140,7 +140,7 @@ LL |     target_env = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:53:5
+  --> $DIR/well-known-values.rs:54:5
    |
 LL |     target_family = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -149,7 +149,7 @@ LL |     target_family = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:55:5
+  --> $DIR/well-known-values.rs:56:5
    |
 LL |     target_feature = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -158,7 +158,7 @@ LL |     target_feature = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:57:5
+  --> $DIR/well-known-values.rs:58:5
    |
 LL |     target_has_atomic = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -167,7 +167,7 @@ LL |     target_has_atomic = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:59:5
+  --> $DIR/well-known-values.rs:60:5
    |
 LL |     target_has_atomic_equal_alignment = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -176,7 +176,7 @@ LL |     target_has_atomic_equal_alignment = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:61:5
+  --> $DIR/well-known-values.rs:62:5
    |
 LL |     target_has_atomic_load_store = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -185,7 +185,7 @@ LL |     target_has_atomic_load_store = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:63:5
+  --> $DIR/well-known-values.rs:64:5
    |
 LL |     target_os = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -194,7 +194,7 @@ LL |     target_os = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:65:5
+  --> $DIR/well-known-values.rs:66:5
    |
 LL |     target_pointer_width = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -203,7 +203,7 @@ LL |     target_pointer_width = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:67:5
+  --> $DIR/well-known-values.rs:68:5
    |
 LL |     target_thread_local = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^----------------------
@@ -214,7 +214,7 @@ LL |     target_thread_local = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:69:5
+  --> $DIR/well-known-values.rs:70:5
    |
 LL |     target_vendor = "_UNEXPECTED_VALUE",
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -223,7 +223,7 @@ LL |     target_vendor = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:71:5
+  --> $DIR/well-known-values.rs:72:5
    |
 LL |     test = "_UNEXPECTED_VALUE",
    |     ^^^^----------------------
@@ -234,7 +234,7 @@ LL |     test = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:73:5
+  --> $DIR/well-known-values.rs:74:5
    |
 LL |     unix = "_UNEXPECTED_VALUE",
    |     ^^^^----------------------
@@ -245,7 +245,7 @@ LL |     unix = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `_UNEXPECTED_VALUE`
-  --> $DIR/well-known-values.rs:75:5
+  --> $DIR/well-known-values.rs:76:5
    |
 LL |     windows = "_UNEXPECTED_VALUE",
    |     ^^^^^^^----------------------
@@ -256,7 +256,7 @@ LL |     windows = "_UNEXPECTED_VALUE",
    = note: see <https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/check-cfg.html> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `linuz`
-  --> $DIR/well-known-values.rs:81:7
+  --> $DIR/well-known-values.rs:82:7
    |
 LL | #[cfg(target_os = "linuz")] // testing that we suggest `linux`
    |       ^^^^^^^^^^^^-------
diff --git a/tests/ui/codegen/duplicated-path-in-error.rs b/tests/ui/codegen/duplicated-path-in-error.rs
new file mode 100644
index 0000000000000..cff20dd9bd639
--- /dev/null
+++ b/tests/ui/codegen/duplicated-path-in-error.rs
@@ -0,0 +1,7 @@
+//@ only-linux
+//@ compile-flags: -Zcodegen-backend=/non-existing-one.so
+
+// This test ensures that the error of the "not found dylib" doesn't duplicate
+// the path of the dylib.
+
+fn main() {}
diff --git a/tests/ui/codegen/duplicated-path-in-error.stderr b/tests/ui/codegen/duplicated-path-in-error.stderr
new file mode 100644
index 0000000000000..d0d34e2f93468
--- /dev/null
+++ b/tests/ui/codegen/duplicated-path-in-error.stderr
@@ -0,0 +1,2 @@
+error: couldn't load codegen backend /non-existing-one.so: cannot open shared object file: No such file or directory
+
diff --git a/tests/ui/consts/const-eval/raw-bytes.32bit.stderr b/tests/ui/consts/const-eval/raw-bytes.32bit.stderr
index c06c30741164a..c1748c2e23769 100644
--- a/tests/ui/consts/const-eval/raw-bytes.32bit.stderr
+++ b/tests/ui/consts/const-eval/raw-bytes.32bit.stderr
@@ -68,7 +68,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/raw-bytes.rs:59:1
    |
 LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
    = note: the raw bytes of the constant (size: 1, align: 1) {
@@ -79,7 +79,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/raw-bytes.rs:61:1
    |
 LL | const NULL_USIZE: NonZero<usize> = unsafe { mem::transmute(0usize) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
    = note: the raw bytes of the constant (size: 4, align: 4) {
diff --git a/tests/ui/consts/const-eval/raw-bytes.64bit.stderr b/tests/ui/consts/const-eval/raw-bytes.64bit.stderr
index 0589280524cab..eb97eab9db756 100644
--- a/tests/ui/consts/const-eval/raw-bytes.64bit.stderr
+++ b/tests/ui/consts/const-eval/raw-bytes.64bit.stderr
@@ -68,7 +68,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/raw-bytes.rs:59:1
    |
 LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
    = note: the raw bytes of the constant (size: 1, align: 1) {
@@ -79,7 +79,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/raw-bytes.rs:61:1
    |
 LL | const NULL_USIZE: NonZero<usize> = unsafe { mem::transmute(0usize) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
    = note: the raw bytes of the constant (size: 8, align: 8) {
diff --git a/tests/ui/consts/const-eval/ub-nonnull.stderr b/tests/ui/consts/const-eval/ub-nonnull.stderr
index 70b961fe1cd4f..ab0fb2abdb309 100644
--- a/tests/ui/consts/const-eval/ub-nonnull.stderr
+++ b/tests/ui/consts/const-eval/ub-nonnull.stderr
@@ -19,7 +19,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-nonnull.rs:24:1
    |
 LL | const NULL_U8: NonZero<u8> = unsafe { mem::transmute(0u8) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
    = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
@@ -30,7 +30,7 @@ error[E0080]: it is undefined behavior to use this value
   --> $DIR/ub-nonnull.rs:26:1
    |
 LL | const NULL_USIZE: NonZero<usize> = unsafe { mem::transmute(0usize) };
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value: encountered 0, but expected something greater or equal to 1
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ constructing invalid value at .0: encountered 0, but expected something greater or equal to 1
    |
    = note: The rules on what exactly is undefined behavior aren't clear, so this check might be overzealous. Please open an issue on the rustc repository if you believe it should not be considered undefined behavior.
    = note: the raw bytes of the constant (size: $SIZE, align: $ALIGN) {
diff --git a/tests/ui/imports/unresolved-seg-after-ambiguous.rs b/tests/ui/imports/unresolved-seg-after-ambiguous.rs
new file mode 100644
index 0000000000000..dcabc528a85ed
--- /dev/null
+++ b/tests/ui/imports/unresolved-seg-after-ambiguous.rs
@@ -0,0 +1,24 @@
+mod a {
+    mod b {
+        mod c {
+            pub struct E;
+        }
+
+        mod d {
+            #[derive(Debug)]
+            pub struct E;
+        }
+
+        pub use self::d::*;
+        pub use self::c::*;
+    }
+
+    pub use self::b::*;
+}
+
+use self::a::E::in_exist;
+//~^ ERROR: unresolved import `self::a::E`
+//~| WARNING: `E` is ambiguous
+//~| WARNING: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+
+fn main() {}
diff --git a/tests/ui/imports/unresolved-seg-after-ambiguous.stderr b/tests/ui/imports/unresolved-seg-after-ambiguous.stderr
new file mode 100644
index 0000000000000..9e0efd4a75f84
--- /dev/null
+++ b/tests/ui/imports/unresolved-seg-after-ambiguous.stderr
@@ -0,0 +1,32 @@
+error[E0432]: unresolved import `self::a::E`
+  --> $DIR/unresolved-seg-after-ambiguous.rs:19:14
+   |
+LL | use self::a::E::in_exist;
+   |              ^ `E` is a struct, not a module
+
+warning: `E` is ambiguous
+  --> $DIR/unresolved-seg-after-ambiguous.rs:19:14
+   |
+LL | use self::a::E::in_exist;
+   |              ^ ambiguous name
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #114095 <https://github.com/rust-lang/rust/issues/114095>
+   = note: ambiguous because of multiple glob imports of a name in the same module
+note: `E` could refer to the struct imported here
+  --> $DIR/unresolved-seg-after-ambiguous.rs:13:17
+   |
+LL |         pub use self::c::*;
+   |                 ^^^^^^^^^^
+   = help: consider adding an explicit import of `E` to disambiguate
+note: `E` could also refer to the struct imported here
+  --> $DIR/unresolved-seg-after-ambiguous.rs:12:17
+   |
+LL |         pub use self::d::*;
+   |                 ^^^^^^^^^^
+   = help: consider adding an explicit import of `E` to disambiguate
+   = note: `#[warn(ambiguous_glob_imports)]` on by default
+
+error: aborting due to 1 previous error; 1 warning emitted
+
+For more information about this error, try `rustc --explain E0432`.
diff --git a/tests/ui/lint/invalid_value.stderr b/tests/ui/lint/invalid_value.stderr
index 955d01bd5d904..e45d061a1f051 100644
--- a/tests/ui/lint/invalid_value.stderr
+++ b/tests/ui/lint/invalid_value.stderr
@@ -320,10 +320,7 @@ error: the type `(NonZero<u32>, i32)` does not permit zero-initialization
   --> $DIR/invalid_value.rs:94:41
    |
 LL |         let _val: (NonZero<u32>, i32) = mem::zeroed();
-   |                                         ^^^^^^^^^^^^^
-   |                                         |
-   |                                         this code causes undefined behavior when executed
-   |                                         help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
+   |                                         ^^^^^^^^^^^^^ this code causes undefined behavior when executed
    |
    = note: `std::num::NonZero<u32>` must be non-null
 
@@ -331,13 +328,9 @@ error: the type `(NonZero<u32>, i32)` does not permit being left uninitialized
   --> $DIR/invalid_value.rs:95:41
    |
 LL |         let _val: (NonZero<u32>, i32) = mem::uninitialized();
-   |                                         ^^^^^^^^^^^^^^^^^^^^
-   |                                         |
-   |                                         this code causes undefined behavior when executed
-   |                                         help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
+   |                                         ^^^^^^^^^^^^^^^^^^^^ this code causes undefined behavior when executed
    |
    = note: `std::num::NonZero<u32>` must be non-null
-   = note: integers must be initialized
 
 error: the type `*const dyn Send` does not permit zero-initialization
   --> $DIR/invalid_value.rs:97:37
@@ -411,10 +404,7 @@ error: the type `OneFruitNonZero` does not permit zero-initialization
   --> $DIR/invalid_value.rs:106:37
    |
 LL |         let _val: OneFruitNonZero = mem::zeroed();
-   |                                     ^^^^^^^^^^^^^
-   |                                     |
-   |                                     this code causes undefined behavior when executed
-   |                                     help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
+   |                                     ^^^^^^^^^^^^^ this code causes undefined behavior when executed
    |
    = note: `OneFruitNonZero` must be non-null
 note: because `std::num::NonZero<u32>` must be non-null (in this field of the only potentially inhabited enum variant)
@@ -427,10 +417,7 @@ error: the type `OneFruitNonZero` does not permit being left uninitialized
   --> $DIR/invalid_value.rs:107:37
    |
 LL |         let _val: OneFruitNonZero = mem::uninitialized();
-   |                                     ^^^^^^^^^^^^^^^^^^^^
-   |                                     |
-   |                                     this code causes undefined behavior when executed
-   |                                     help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
+   |                                     ^^^^^^^^^^^^^^^^^^^^ this code causes undefined behavior when executed
    |
    = note: `OneFruitNonZero` must be non-null
 note: because `std::num::NonZero<u32>` must be non-null (in this field of the only potentially inhabited enum variant)
@@ -438,7 +425,6 @@ note: because `std::num::NonZero<u32>` must be non-null (in this field of the on
    |
 LL |     Banana(NonZero<u32>),
    |            ^^^^^^^^^^^^
-   = note: integers must be initialized
 
 error: the type `bool` does not permit being left uninitialized
   --> $DIR/invalid_value.rs:111:26
@@ -607,10 +593,7 @@ error: the type `NonZero<u32>` does not permit zero-initialization
   --> $DIR/invalid_value.rs:153:34
    |
 LL |         let _val: NonZero<u32> = mem::transmute(0);
-   |                                  ^^^^^^^^^^^^^^^^^
-   |                                  |
-   |                                  this code causes undefined behavior when executed
-   |                                  help: use `MaybeUninit<T>` instead, and only call `assume_init` after initialization is done
+   |                                  ^^^^^^^^^^^^^^^^^ this code causes undefined behavior when executed
    |
    = note: `std::num::NonZero<u32>` must be non-null
 
diff --git a/tests/ui/lint/use-redundant/use-redundant-issue-71450.rs b/tests/ui/lint/use-redundant/use-redundant-issue-71450.rs
new file mode 100644
index 0000000000000..d0fb3454d3f2b
--- /dev/null
+++ b/tests/ui/lint/use-redundant/use-redundant-issue-71450.rs
@@ -0,0 +1,45 @@
+//@ check-pass
+
+#![warn(unused_imports)]
+
+mod foo {
+    use std::fmt;
+
+    pub struct String;
+
+    impl String {
+        pub fn new() -> String {
+            String{}
+        }
+    }
+
+    impl fmt::Display for String {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            write!(f, "String")
+        }
+    }
+}
+
+fn main() {
+
+    {
+        use std::string::String; //~ WARNING the item `String` is imported redundantly
+        // 'String' from 'std::string::String'.
+        let s = String::new();
+        println!("{}", s);
+    }
+
+    {
+        // 'String' from 'std::string::String'.
+        let s = String::new();
+        println!("{}", s);
+    }
+
+    {
+        use foo::*;
+        // 'String' from 'foo::String'.
+        let s = String::new();
+        println!("{}", s);
+    }
+
+}
diff --git a/tests/ui/lint/use-redundant/use-redundant-issue-71450.stderr b/tests/ui/lint/use-redundant/use-redundant-issue-71450.stderr
new file mode 100644
index 0000000000000..b8832a3178371
--- /dev/null
+++ b/tests/ui/lint/use-redundant/use-redundant-issue-71450.stderr
@@ -0,0 +1,17 @@
+warning: the item `String` is imported redundantly
+  --> $DIR/use-redundant-issue-71450.rs:26:13
+   |
+LL |         use std::string::String;
+   |             ^^^^^^^^^^^^^^^^^^^
+  --> $SRC_DIR/std/src/prelude/mod.rs:LL:COL
+   |
+   = note: the item `String` is already defined here
+   |
+note: the lint level is defined here
+  --> $DIR/use-redundant-issue-71450.rs:3:9
+   |
+LL | #![warn(unused_imports)]
+   |         ^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/lint/use-redundant/use-redundant-issue-78894.rs b/tests/ui/lint/use-redundant/use-redundant-issue-78894.rs
new file mode 100644
index 0000000000000..09c87bc37a630
--- /dev/null
+++ b/tests/ui/lint/use-redundant/use-redundant-issue-78894.rs
@@ -0,0 +1,48 @@
+//@ check-pass
+//@ edition:2018
+
+#![warn(unused_imports)]
+
+mod foo {
+    macro_rules! foo1 {
+        () => ();
+    }
+
+    pub(crate) use foo1;
+}
+
+fn main ()
+{
+    bar!();
+
+    macro_rules! bar {
+        () => ();
+    }
+
+    use bar;
+
+    mod m {
+        bar1!();
+
+        macro_rules! bar1 {
+            () => ();
+        }
+
+        use bar1;
+    }
+
+    {
+        foo::foo1!();
+    }
+
+    {
+        use foo::foo1;
+        foo1!();
+    }
+
+    {
+        use foo::foo1; //~ WARNING unused import: `foo::foo1`
+        foo::foo1!();
+    }
+
+}
diff --git a/tests/ui/lint/use-redundant/use-redundant-issue-78894.stderr b/tests/ui/lint/use-redundant/use-redundant-issue-78894.stderr
new file mode 100644
index 0000000000000..78dfe364223d4
--- /dev/null
+++ b/tests/ui/lint/use-redundant/use-redundant-issue-78894.stderr
@@ -0,0 +1,14 @@
+warning: unused import: `foo::foo1`
+  --> $DIR/use-redundant-issue-78894.rs:44:13
+   |
+LL |         use foo::foo1;
+   |             ^^^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/use-redundant-issue-78894.rs:4:9
+   |
+LL | #![warn(unused_imports)]
+   |         ^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+
diff --git a/tests/ui/print_type_sizes/niche-filling.stdout b/tests/ui/print_type_sizes/niche-filling.stdout
index 53a58ccc4eef8..eeb5de5324121 100644
--- a/tests/ui/print_type_sizes/niche-filling.stdout
+++ b/tests/ui/print_type_sizes/niche-filling.stdout
@@ -68,6 +68,8 @@ print-type-size type: `Union2<std::num::NonZero<u32>, u32>`: 4 bytes, alignment:
 print-type-size     variant `Union2`: 4 bytes
 print-type-size         field `.a`: 4 bytes
 print-type-size         field `.b`: 4 bytes, offset: 0 bytes, alignment: 4 bytes
+print-type-size type: `core::num::nonzero::private::NonZeroU32Inner`: 4 bytes, alignment: 4 bytes
+print-type-size     field `.0`: 4 bytes
 print-type-size type: `std::num::NonZero<u32>`: 4 bytes, alignment: 4 bytes
 print-type-size     field `.0`: 4 bytes
 print-type-size type: `std::option::Option<std::num::NonZero<u32>>`: 4 bytes, alignment: 4 bytes
diff --git a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.rs b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.rs
index 4c881dd133086..3117060cef0d2 100644
--- a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.rs
+++ b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.rs
@@ -15,7 +15,7 @@ impl Trait for Bar {
     type Assoc = impl std::fmt::Debug;
     fn foo() -> Foo {
         Foo { field: () }
-        //~^ ERROR: item constrains opaque type that is not in its signature
+        //~^ ERROR: mismatched types
     }
 }
 
diff --git a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.stderr b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.stderr
index 5c53dfa3a7500..4910e794e8d6e 100644
--- a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.stderr
+++ b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field2.stderr
@@ -1,11 +1,15 @@
-error: item constrains opaque type that is not in its signature
+error[E0308]: mismatched types
   --> $DIR/hidden_behind_struct_field2.rs:17:22
    |
+LL |     type Assoc = impl std::fmt::Debug;
+   |                  -------------------- the expected opaque type
+LL |     fn foo() -> Foo {
 LL |         Foo { field: () }
-   |                      ^^
+   |                      ^^ expected opaque type, found `()`
    |
-   = note: this item must mention the opaque type in its signature in order to be able to register hidden types
-note: this item must mention the opaque type in its signature in order to be able to register hidden types
+   = note: expected opaque type `<Bar as Trait>::Assoc`
+                found unit type `()`
+note: this item must have the opaque type in its signature in order to be able to register hidden types
   --> $DIR/hidden_behind_struct_field2.rs:16:8
    |
 LL |     fn foo() -> Foo {
@@ -13,3 +17,4 @@ LL |     fn foo() -> Foo {
 
 error: aborting due to 1 previous error
 
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.rs b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.rs
index 1278563a92c46..c1f135994121e 100644
--- a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.rs
+++ b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.rs
@@ -17,7 +17,7 @@ impl Trait for Bar {
     type Assoc = impl Iterator<Item = Foo>;
     fn foo() -> Self::Assoc {
         vec![Foo { field: () }].into_iter()
-        //~^ ERROR item constrains opaque type that is not in its signature
+        //~^ ERROR mismatched types
     }
 }
 
diff --git a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.stderr b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.stderr
index 0570e0303c633..f10ccc0029973 100644
--- a/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.stderr
+++ b/tests/ui/type-alias-impl-trait/hidden_behind_struct_field3.stderr
@@ -1,11 +1,15 @@
-error: item constrains opaque type that is not in its signature
+error[E0308]: mismatched types
   --> $DIR/hidden_behind_struct_field3.rs:19:27
    |
+LL |     type Assoc2 = impl std::fmt::Debug;
+   |                   -------------------- the expected opaque type
+...
 LL |         vec![Foo { field: () }].into_iter()
-   |                           ^^
+   |                           ^^ expected opaque type, found `()`
    |
-   = note: this item must mention the opaque type in its signature in order to be able to register hidden types
-note: this item must mention the opaque type in its signature in order to be able to register hidden types
+   = note: expected opaque type `<Bar as Trait>::Assoc2`
+                found unit type `()`
+note: this item must have the opaque type in its signature in order to be able to register hidden types
   --> $DIR/hidden_behind_struct_field3.rs:18:8
    |
 LL |     fn foo() -> Self::Assoc {
@@ -13,3 +17,4 @@ LL |     fn foo() -> Self::Assoc {
 
 error: aborting due to 1 previous error
 
+For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/union/unnamed-fields/unnamed-enum-field-issue-121757.rs b/tests/ui/union/unnamed-fields/unnamed-enum-field-issue-121757.rs
new file mode 100644
index 0000000000000..5d15ec4cffdb9
--- /dev/null
+++ b/tests/ui/union/unnamed-fields/unnamed-enum-field-issue-121757.rs
@@ -0,0 +1,25 @@
+type NodeId = u32;
+struct Type<'a>(std::marker::PhantomData::<&'a ()>);
+
+type Ast<'ast> = &'ast AstStructure<'ast>;
+
+struct AstStructure<'ast> {
+//~^ ERROR struct with unnamed fields must have `#[repr(C)]` representation
+    id: NodeId,
+    _: AstKind<'ast>
+//~^ ERROR unnamed fields are not yet fully implemented [E0658]
+//~^^ ERROR unnamed fields can only have struct or union types
+}
+
+enum AstKind<'ast> {
+    ExprInt,
+    ExprLambda(Ast<'ast>),
+}
+
+fn compute_types<'tcx,'ast>(ast: Ast<'ast>) -> Type<'tcx>
+{
+    match ast.kind {}
+//~^ ERROR no field `kind` on type `&'ast AstStructure<'ast>` [E0609]
+}
+
+fn main() {}
diff --git a/tests/ui/union/unnamed-fields/unnamed-enum-field-issue-121757.stderr b/tests/ui/union/unnamed-fields/unnamed-enum-field-issue-121757.stderr
new file mode 100644
index 0000000000000..4ea910202de98
--- /dev/null
+++ b/tests/ui/union/unnamed-fields/unnamed-enum-field-issue-121757.stderr
@@ -0,0 +1,45 @@
+error[E0658]: unnamed fields are not yet fully implemented
+  --> $DIR/unnamed-enum-field-issue-121757.rs:9:5
+   |
+LL |     _: AstKind<'ast>
+   |     ^
+   |
+   = note: see issue #49804 <https://github.com/rust-lang/rust/issues/49804> for more information
+   = help: add `#![feature(unnamed_fields)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: struct with unnamed fields must have `#[repr(C)]` representation
+  --> $DIR/unnamed-enum-field-issue-121757.rs:6:1
+   |
+LL | struct AstStructure<'ast> {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^ struct `AstStructure` defined here
+   |
+note: unnamed field defined here
+  --> $DIR/unnamed-enum-field-issue-121757.rs:9:5
+   |
+LL |     _: AstKind<'ast>
+   |     ^^^^^^^^^^^^^^^^
+help: add `#[repr(C)]` to this struct
+   |
+LL + #[repr(C)]
+LL | struct AstStructure<'ast> {
+   |
+
+error: unnamed fields can only have struct or union types
+  --> $DIR/unnamed-enum-field-issue-121757.rs:9:5
+   |
+LL |     _: AstKind<'ast>
+   |     ^^^^^^^^^^^^^^^^
+
+error[E0609]: no field `kind` on type `&'ast AstStructure<'ast>`
+  --> $DIR/unnamed-enum-field-issue-121757.rs:21:15
+   |
+LL |     match ast.kind {}
+   |               ^^^^ unknown field
+   |
+   = note: available fields are: `id`, `_`
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0609, E0658.
+For more information about an error, try `rustc --explain E0609`.