diff --git a/.github/ISSUE_TEMPLATE/library_tracking_issue.md b/.github/ISSUE_TEMPLATE/library_tracking_issue.md
index 934312662beb6..d56da9d5d025a 100644
--- a/.github/ISSUE_TEMPLATE/library_tracking_issue.md
+++ b/.github/ISSUE_TEMPLATE/library_tracking_issue.md
@@ -2,7 +2,7 @@
 name: Library Tracking Issue
 about: A tracking issue for an unstable library feature.
 title: Tracking Issue for XXX
-labels: C-tracking-issue, T-libs-api
+labels: C-tracking-issue, T-libs-api, S-tracking-unimplemented
 ---
 <!--
 Thank you for creating a tracking issue!
@@ -49,6 +49,8 @@ For larger features, more steps might be involved.
 If the feature is changed later, please add those PRs here as well.
 -->
 
+(Remember to update the `S-tracking-*` label when checking boxes.)
+
 - [ ] Implementation: #...
 - [ ] Final comment period (FCP)[^1]
 - [ ] Stabilization PR
diff --git a/Cargo.lock b/Cargo.lock
index 818743b135b51..2175f0871e00c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -718,7 +718,6 @@ name = "compiletest"
 version = "0.0.0"
 dependencies = [
  "anstyle-svg",
- "anyhow",
  "build_helper",
  "colored",
  "diff",
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 794502d7aaee3..bd13c413a4df4 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -647,9 +647,9 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     #[rustc_lint_diagnostics]
     pub fn note_expected_found(
         &mut self,
-        expected_label: &dyn fmt::Display,
+        expected_label: &str,
         expected: DiagStyledString,
-        found_label: &dyn fmt::Display,
+        found_label: &str,
         found: DiagStyledString,
     ) -> &mut Self {
         self.note_expected_found_extra(
@@ -665,9 +665,9 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     #[rustc_lint_diagnostics]
     pub fn note_expected_found_extra(
         &mut self,
-        expected_label: &dyn fmt::Display,
+        expected_label: &str,
         expected: DiagStyledString,
-        found_label: &dyn fmt::Display,
+        found_label: &str,
         found: DiagStyledString,
         expected_extra: DiagStyledString,
         found_extra: DiagStyledString,
diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index e9cd22435d958..a33707649fcf5 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -14,6 +14,7 @@
 //! At present, however, we do run collection across all items in the
 //! crate as a kind of pass. This should eventually be factored away.
 
+use std::assert_matches::assert_matches;
 use std::cell::Cell;
 use std::iter;
 use std::ops::Bound;
@@ -1344,7 +1345,8 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_, ty::PolyFn
             compute_sig_of_foreign_fn_decl(tcx, def_id, sig.decl, abi, sig.header.safety())
         }
 
-        Ctor(data) | Variant(hir::Variant { data, .. }) if data.ctor().is_some() => {
+        Ctor(data) => {
+            assert_matches!(data.ctor(), Some(_));
             let adt_def_id = tcx.hir_get_parent_item(hir_id).def_id.to_def_id();
             let ty = tcx.type_of(adt_def_id).instantiate_identity();
             let inputs = data.fields().iter().map(|f| tcx.type_of(f.def_id).instantiate_identity());
diff --git a/compiler/rustc_hir_analysis/src/variance/mod.rs b/compiler/rustc_hir_analysis/src/variance/mod.rs
index 0800d99e9452e..dbba45dc7bb58 100644
--- a/compiler/rustc_hir_analysis/src/variance/mod.rs
+++ b/compiler/rustc_hir_analysis/src/variance/mod.rs
@@ -44,13 +44,13 @@ fn variances_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Variance] {
         return &[];
     }
 
-    match tcx.def_kind(item_def_id) {
+    let kind = tcx.def_kind(item_def_id);
+    match kind {
         DefKind::Fn
         | DefKind::AssocFn
         | DefKind::Enum
         | DefKind::Struct
         | DefKind::Union
-        | DefKind::Variant
         | DefKind::Ctor(..) => {
             // These are inferred.
             let crate_map = tcx.crate_variances(());
@@ -89,7 +89,11 @@ fn variances_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId) -> &[ty::Variance] {
     }
 
     // Variance not relevant.
-    span_bug!(tcx.def_span(item_def_id), "asked to compute variance for wrong kind of item");
+    span_bug!(
+        tcx.def_span(item_def_id),
+        "asked to compute variance for {}",
+        kind.descr(item_def_id.to_def_id())
+    );
 }
 
 #[derive(Debug, Copy, Clone)]
diff --git a/compiler/rustc_lint/src/lints.rs b/compiler/rustc_lint/src/lints.rs
index 55d010e6d34aa..51214c8e8a4cf 100644
--- a/compiler/rustc_lint/src/lints.rs
+++ b/compiler/rustc_lint/src/lints.rs
@@ -513,7 +513,7 @@ impl Subdiagnostic for BuiltinClashingExternSub<'_> {
         expected_str.push(self.expected.fn_sig(self.tcx).to_string(), false);
         let mut found_str = DiagStyledString::new();
         found_str.push(self.found.fn_sig(self.tcx).to_string(), true);
-        diag.note_expected_found(&"", expected_str, &"", found_str);
+        diag.note_expected_found("", expected_str, "", found_str);
     }
 }
 
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index 167122a9793ac..55bb984c5b69f 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1099,7 +1099,6 @@ fn should_encode_variances<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, def_kind: Def
         DefKind::Struct
         | DefKind::Union
         | DefKind::Enum
-        | DefKind::Variant
         | DefKind::OpaqueTy
         | DefKind::Fn
         | DefKind::Ctor(..)
@@ -1109,6 +1108,7 @@ fn should_encode_variances<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId, def_kind: Def
             matches!(tcx.opt_rpitit_info(def_id), Some(ty::ImplTraitInTraitData::Trait { .. }))
         }
         DefKind::Mod
+        | DefKind::Variant
         | DefKind::Field
         | DefKind::AssocConst
         | DefKind::TyParam
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/region.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/region.rs
index c7f0a88f951a8..fcb98f740b01a 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/region.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/region.rs
@@ -967,7 +967,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 format!("...so that the {}", sup_trace.cause.as_requirement_str()),
             );
 
-            err.note_expected_found(&"", sup_expected, &"", sup_found);
+            err.note_expected_found("", sup_expected, "", sup_found);
             return if sub_region.is_error() | sup_region.is_error() {
                 err.delay_as_bug()
             } else {
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
index bc45fc11e9bbe..5648021f6134e 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs
@@ -2,6 +2,7 @@ use core::ops::ControlFlow;
 use std::borrow::Cow;
 use std::path::PathBuf;
 
+use rustc_abi::ExternAbi;
 use rustc_ast::TraitObjectSyntax;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::unord::UnordSet;
@@ -2799,32 +2800,57 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         }
 
         // Note any argument mismatches
-        let given_ty = params.skip_binder();
+        let ty::Tuple(given) = *params.skip_binder().kind() else {
+            return;
+        };
+
         let expected_ty = trait_pred.skip_binder().trait_ref.args.type_at(1);
-        if let ty::Tuple(given) = given_ty.kind()
-            && let ty::Tuple(expected) = expected_ty.kind()
-        {
-            if expected.len() != given.len() {
-                // Note number of types that were expected and given
-                err.note(
-                    format!(
-                        "expected a closure taking {} argument{}, but one taking {} argument{} was given",
-                        given.len(),
-                        pluralize!(given.len()),
-                        expected.len(),
-                        pluralize!(expected.len()),
-                    )
-                );
-            } else if !self.same_type_modulo_infer(given_ty, expected_ty) {
-                // Print type mismatch
-                let (expected_args, given_args) = self.cmp(given_ty, expected_ty);
-                err.note_expected_found(
-                    &"a closure with arguments",
-                    expected_args,
-                    &"a closure with arguments",
-                    given_args,
-                );
-            }
+        let ty::Tuple(expected) = *expected_ty.kind() else {
+            return;
+        };
+
+        if expected.len() != given.len() {
+            // Note number of types that were expected and given
+            err.note(format!(
+                "expected a closure taking {} argument{}, but one taking {} argument{} was given",
+                given.len(),
+                pluralize!(given.len()),
+                expected.len(),
+                pluralize!(expected.len()),
+            ));
+            return;
+        }
+
+        let given_ty = Ty::new_fn_ptr(
+            self.tcx,
+            params.rebind(self.tcx.mk_fn_sig(
+                given,
+                self.tcx.types.unit,
+                false,
+                hir::Safety::Safe,
+                ExternAbi::Rust,
+            )),
+        );
+        let expected_ty = Ty::new_fn_ptr(
+            self.tcx,
+            trait_pred.rebind(self.tcx.mk_fn_sig(
+                expected,
+                self.tcx.types.unit,
+                false,
+                hir::Safety::Safe,
+                ExternAbi::Rust,
+            )),
+        );
+
+        if !self.same_type_modulo_infer(given_ty, expected_ty) {
+            // Print type mismatch
+            let (expected_args, given_args) = self.cmp(expected_ty, given_ty);
+            err.note_expected_found(
+                "a closure with signature",
+                expected_args,
+                "a closure with signature",
+                given_args,
+            );
         }
     }
 
diff --git a/compiler/rustc_trait_selection/src/errors.rs b/compiler/rustc_trait_selection/src/errors.rs
index 9f7bfe5101ab2..bb4aba9d29e42 100644
--- a/compiler/rustc_trait_selection/src/errors.rs
+++ b/compiler/rustc_trait_selection/src/errors.rs
@@ -415,7 +415,7 @@ impl Subdiagnostic for RegionOriginNote<'_> {
                 label_or_note(span, fluent::trait_selection_subtype);
                 diag.arg("requirement", requirement);
 
-                diag.note_expected_found(&"", expected, &"", found);
+                diag.note_expected_found("", expected, "", found);
             }
             RegionOriginNote::WithRequirement { span, requirement, expected_found: None } => {
                 // FIXME: this really should be handled at some earlier stage. Our
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 9d5eb551fe6f7..69e7b2a43ff9b 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -317,7 +317,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     obligation.cause.clone(),
                     obligation.recursion_depth + 1,
                     obligation.param_env,
-                    obligation.predicate.rebind(trait_ref),
+                    trait_ref,
                 )
             };
 
@@ -343,7 +343,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                     obligation.cause.clone(),
                     obligation.recursion_depth + 1,
                     obligation.param_env,
-                    obligation.predicate.rebind(outlives),
+                    outlives,
                 )
             };
 
@@ -404,7 +404,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             }
         }
 
-        let predicate = obligation.predicate.skip_binder();
+        let predicate = self.infcx.enter_forall_and_leak_universe(obligation.predicate);
 
         let mut assume = predicate.trait_ref.args.const_at(2);
         // FIXME(mgca): We should shallowly normalize this.
diff --git a/compiler/rustc_ty_utils/src/implied_bounds.rs b/compiler/rustc_ty_utils/src/implied_bounds.rs
index 088d5e76b8685..492a20a7d5b70 100644
--- a/compiler/rustc_ty_utils/src/implied_bounds.rs
+++ b/compiler/rustc_ty_utils/src/implied_bounds.rs
@@ -4,9 +4,9 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
-use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, Ty, TyCtxt, fold_regions};
+use rustc_middle::{bug, span_bug};
 use rustc_span::Span;
 
 pub(crate) fn provide(providers: &mut Providers) {
@@ -21,7 +21,8 @@ pub(crate) fn provide(providers: &mut Providers) {
 }
 
 fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'tcx>, Span)] {
-    match tcx.def_kind(def_id) {
+    let kind = tcx.def_kind(def_id);
+    match kind {
         DefKind::Fn => {
             let sig = tcx.fn_sig(def_id).instantiate_identity();
             let liberated_sig = tcx.liberate_late_bound_regions(def_id.to_def_id(), sig);
@@ -121,32 +122,38 @@ fn assumed_wf_types<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> &'tcx [(Ty<'
             }
         }
         DefKind::AssocConst | DefKind::AssocTy => tcx.assumed_wf_types(tcx.local_parent(def_id)),
-        DefKind::OpaqueTy => bug!("implied bounds are not defined for opaques"),
-        DefKind::Mod
+        DefKind::Static { .. }
+        | DefKind::Const
+        | DefKind::AnonConst
+        | DefKind::InlineConst
         | DefKind::Struct
         | DefKind::Union
         | DefKind::Enum
-        | DefKind::Variant
         | DefKind::Trait
-        | DefKind::TyAlias
-        | DefKind::ForeignTy
         | DefKind::TraitAlias
+        | DefKind::TyAlias => ty::List::empty(),
+        DefKind::OpaqueTy
+        | DefKind::Mod
+        | DefKind::Variant
+        | DefKind::ForeignTy
         | DefKind::TyParam
-        | DefKind::Const
         | DefKind::ConstParam
-        | DefKind::Static { .. }
         | DefKind::Ctor(_, _)
         | DefKind::Macro(_)
         | DefKind::ExternCrate
         | DefKind::Use
         | DefKind::ForeignMod
-        | DefKind::AnonConst
-        | DefKind::InlineConst
         | DefKind::Field
         | DefKind::LifetimeParam
         | DefKind::GlobalAsm
         | DefKind::Closure
-        | DefKind::SyntheticCoroutineBody => ty::List::empty(),
+        | DefKind::SyntheticCoroutineBody => {
+            span_bug!(
+                tcx.def_span(def_id),
+                "`assumed_wf_types` not defined for {} `{def_id:?}`",
+                kind.descr(def_id.to_def_id())
+            );
+        }
     }
 }
 
diff --git a/compiler/rustc_ty_utils/src/opaque_types.rs b/compiler/rustc_ty_utils/src/opaque_types.rs
index 3aad97d86cca1..cd730aeeea900 100644
--- a/compiler/rustc_ty_utils/src/opaque_types.rs
+++ b/compiler/rustc_ty_utils/src/opaque_types.rs
@@ -3,10 +3,10 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit;
 use rustc_hir::intravisit::Visitor;
-use rustc_middle::bug;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::util::{CheckRegions, NotUniqueParam};
 use rustc_middle::ty::{self, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor};
+use rustc_middle::{bug, span_bug};
 use rustc_span::Span;
 use tracing::{instrument, trace};
 
@@ -320,9 +320,12 @@ fn opaque_types_defined_by<'tcx>(
         | DefKind::AnonConst => {
             collector.collect_taits_declared_in_body();
         }
+        // Closures and coroutines are type checked with their parent
+        DefKind::Closure | DefKind::InlineConst => {
+            collector.opaques.extend(tcx.opaque_types_defined_by(tcx.local_parent(item)));
+        }
+        DefKind::AssocTy | DefKind::TyAlias | DefKind::GlobalAsm => {}
         DefKind::OpaqueTy
-        | DefKind::TyAlias
-        | DefKind::AssocTy
         | DefKind::Mod
         | DefKind::Struct
         | DefKind::Union
@@ -340,12 +343,13 @@ fn opaque_types_defined_by<'tcx>(
         | DefKind::ForeignMod
         | DefKind::Field
         | DefKind::LifetimeParam
-        | DefKind::GlobalAsm
         | DefKind::Impl { .. }
-        | DefKind::SyntheticCoroutineBody => {}
-        // Closures and coroutines are type checked with their parent
-        DefKind::Closure | DefKind::InlineConst => {
-            collector.opaques.extend(tcx.opaque_types_defined_by(tcx.local_parent(item)));
+        | DefKind::SyntheticCoroutineBody => {
+            span_bug!(
+                tcx.def_span(item),
+                "`opaque_types_defined_by` not defined for {} `{item:?}`",
+                kind.descr(item.to_def_id())
+            );
         }
     }
     tcx.mk_local_def_ids(&collector.opaques)
diff --git a/compiler/rustc_ty_utils/src/sig_types.rs b/compiler/rustc_ty_utils/src/sig_types.rs
index 5bb96f90029ae..dc6009116ac57 100644
--- a/compiler/rustc_ty_utils/src/sig_types.rs
+++ b/compiler/rustc_ty_utils/src/sig_types.rs
@@ -116,7 +116,7 @@ pub fn walk_types<'tcx, V: SpannedTypeVisitor<'tcx>>(
                 "{kind:?} has not seen any uses of `walk_types` yet, ping oli-obk if you'd like any help"
             )
         }
-        // These don't have any types.
+        // These don't have any types, but are visited during privacy checking.
         | DefKind::ExternCrate
         | DefKind::ForeignMod
         | DefKind::ForeignTy
diff --git a/library/core/src/intrinsics/mod.rs b/library/core/src/intrinsics/mod.rs
index 933b5aec70c63..f81a6ca69ada0 100644
--- a/library/core/src/intrinsics/mod.rs
+++ b/library/core/src/intrinsics/mod.rs
@@ -3720,7 +3720,7 @@ pub const fn ptr_metadata<P: ptr::Pointee<Metadata = M> + ?Sized, M>(ptr: *const
 /// [`Vec::append`]: ../../std/vec/struct.Vec.html#method.append
 #[doc(alias = "memcpy")]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_allowed_through_unstable_modules = "import this function via `std::mem` instead"]
+#[rustc_allowed_through_unstable_modules = "import this function via `std::ptr` instead"]
 #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.83.0")]
 #[inline(always)]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
@@ -3823,7 +3823,7 @@ pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: us
 /// ```
 #[doc(alias = "memmove")]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_allowed_through_unstable_modules = "import this function via `std::mem` instead"]
+#[rustc_allowed_through_unstable_modules = "import this function via `std::ptr` instead"]
 #[rustc_const_stable(feature = "const_intrinsic_copy", since = "1.83.0")]
 #[inline(always)]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
@@ -3903,7 +3903,7 @@ pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) {
 /// ```
 #[doc(alias = "memset")]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[rustc_allowed_through_unstable_modules = "import this function via `std::mem` instead"]
+#[rustc_allowed_through_unstable_modules = "import this function via `std::ptr` instead"]
 #[rustc_const_stable(feature = "const_ptr_write", since = "1.83.0")]
 #[inline(always)]
 #[cfg_attr(miri, track_caller)] // even without panics, this helps for Miri backtraces
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index d83731e0f0898..e270c92fcab60 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -189,7 +189,7 @@ pub enum GccCiMode {
 ///
 /// Note that this structure is not decoded directly into, but rather it is
 /// filled out from the decoded forms of the structs below. For documentation
-/// each field, see the corresponding fields in
+/// on each field, see the corresponding fields in
 /// `bootstrap.example.toml`.
 #[derive(Default, Clone)]
 pub struct Config {
diff --git a/src/doc/rustc-dev-guide/book.toml b/src/doc/rustc-dev-guide/book.toml
index eb2f6806b96fc..b84b1e7548a86 100644
--- a/src/doc/rustc-dev-guide/book.toml
+++ b/src/doc/rustc-dev-guide/book.toml
@@ -1,6 +1,6 @@
 [book]
 title = "Rust Compiler Development Guide"
-author = "The Rust Project Developers"
+authors = ["The Rust Project Developers"]
 description = "A guide to developing the Rust compiler (rustc)"
 
 [build]
diff --git a/src/doc/rustc-dev-guide/rust-version b/src/doc/rustc-dev-guide/rust-version
index d7c20d8ce620e..a6f2951087975 100644
--- a/src/doc/rustc-dev-guide/rust-version
+++ b/src/doc/rustc-dev-guide/rust-version
@@ -1 +1 @@
-ae9173d7dd4a31806c950c90dcc331f1508b4d17
+25a615bf829b9f6d6f22da537e3851043f92e5f2
diff --git a/src/doc/rustc-dev-guide/src/backend/libs-and-metadata.md b/src/doc/rustc-dev-guide/src/backend/libs-and-metadata.md
index 556b3fdf8f84f..513df1650c387 100644
--- a/src/doc/rustc-dev-guide/src/backend/libs-and-metadata.md
+++ b/src/doc/rustc-dev-guide/src/backend/libs-and-metadata.md
@@ -110,7 +110,7 @@ See [`compute_hir_hash`] for where the hash is actually computed.
 
 [SVH]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_data_structures/svh/struct.Svh.html
 [incremental compilation]: ../queries/incremental-compilation.md
-[`compute_hir_hash`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast_lowering/struct.LoweringContext.html#method.compute_hir_hash
+[`compute_hir_hash`]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_ast_lowering/fn.compute_hir_hash.html
 
 ### Stable Crate Id
 
diff --git a/src/doc/rustc-dev-guide/src/rustdoc.md b/src/doc/rustc-dev-guide/src/rustdoc.md
index 320dc9d582584..e36d6a388a981 100644
--- a/src/doc/rustc-dev-guide/src/rustdoc.md
+++ b/src/doc/rustc-dev-guide/src/rustdoc.md
@@ -90,7 +90,9 @@ does is call the `main()` that's in this crate's `lib.rs`, though.)
   are in `tests/rustdoc-gui`. These use a [NodeJS tool called
   browser-UI-test](https://github.com/GuillaumeGomez/browser-UI-test/) that uses
   puppeteer to run tests in a headless browser and check rendering and
-  interactivity.
+  interactivity.  For information on how to write this form of test,
+  see [`tests/rustdoc-gui/README.md`][rustdoc-gui-readme]
+  as well as [the description of the `.goml` format][goml-script]
 * Additionally, JavaScript type annotations are written using [TypeScript-flavored JSDoc]
   comments and an external d.ts file. The code itself is plain, valid JavaScript; we only
   use tsc as a linter.
@@ -100,6 +102,8 @@ does is call the `main()` that's in this crate's `lib.rs`, though.)
   [These tests have several extra directives available to them](./rustdoc-internals/rustdoc-test-suite.md).
 
 [TypeScript-flavored JSDoc]: https://www.typescriptlang.org/docs/handbook/jsdoc-supported-types.html
+[rustdoc-gui-readme]: https://github.com/rust-lang/rust/blob/master/tests/rustdoc-gui/README.md
+[goml-script]: https://github.com/GuillaumeGomez/browser-UI-test/blob/master/goml-script.md
 
 ## Constraints
 
diff --git a/src/doc/rustc-dev-guide/src/tests/directives.md b/src/doc/rustc-dev-guide/src/tests/directives.md
index 81aa35f1a4653..8e4a710178ed9 100644
--- a/src/doc/rustc-dev-guide/src/tests/directives.md
+++ b/src/doc/rustc-dev-guide/src/tests/directives.md
@@ -6,7 +6,8 @@
 FIXME(jieyouxu) completely revise this chapter.
 -->
 
-Directives are special comments that tell compiletest how to build and interpret a test. They must appear before the Rust source in the test. They may also appear in `rmake.rs` [run-make tests](compiletest.md#run-make-tests).
+Directives are special comments that tell compiletest how to build and interpret a test.
+They may also appear in `rmake.rs` [run-make tests](compiletest.md#run-make-tests).
 
 They are normally put after the short comment that explains the point of this
 test. Compiletest test suites use `//@` to signal that a comment is a directive.
diff --git a/src/doc/rustc-dev-guide/src/tests/ui.md b/src/doc/rustc-dev-guide/src/tests/ui.md
index 407862d48afd3..e862a07cae0a2 100644
--- a/src/doc/rustc-dev-guide/src/tests/ui.md
+++ b/src/doc/rustc-dev-guide/src/tests/ui.md
@@ -335,8 +335,9 @@ But for strict testing, try to use the `ERROR` annotation as much as possible,
 including `//~?` annotations for diagnostics without span.
 For compile time diagnostics `error-pattern` should very rarely be necessary.
 
-Per-line annotations (`//~`) are still checked in tests using `error-pattern`,
-to opt out of these checks in exceptional cases use `//@ compile-flags: --error-format=human`.
+Per-line annotations (`//~`) are still checked in tests using `error-pattern`.
+To opt out of these checks, use `//@ compile-flags: --error-format=human`.
+Do that only in exceptional cases.
 
 ### Error levels
 
diff --git a/src/tools/compiletest/Cargo.toml b/src/tools/compiletest/Cargo.toml
index 4f8e475e7625f..06e618c2d254b 100644
--- a/src/tools/compiletest/Cargo.toml
+++ b/src/tools/compiletest/Cargo.toml
@@ -7,25 +7,26 @@ edition = "2021"
 doctest = false
 
 [dependencies]
+# tidy-alphabetical-start
 anstyle-svg = "0.1.3"
+build_helper = { path = "../../build_helper" }
 colored = "2"
 diff = "0.1.10"
-unified-diff = "0.2.1"
 getopts = "0.2"
+glob = "0.3.0"
+home = "0.5.5"
 indexmap = "2.0.0"
 miropt-test-tools = { path = "../miropt-test-tools" }
-build_helper = { path = "../../build_helper" }
-tracing = "0.1"
-tracing-subscriber = { version = "0.3.3", default-features = false, features = ["ansi", "env-filter", "fmt", "parking_lot", "smallvec"] }
 regex = "1.0"
+rustfix = "0.8.1"
 semver = { version = "1.0.23", features = ["serde"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-rustfix = "0.8.1"
+tracing = "0.1"
+tracing-subscriber = { version = "0.3.3", default-features = false, features = ["ansi", "env-filter", "fmt", "parking_lot", "smallvec"] }
+unified-diff = "0.2.1"
 walkdir = "2"
-glob = "0.3.0"
-anyhow = "1"
-home = "0.5.5"
+# tidy-alphabetical-end
 
 [target.'cfg(unix)'.dependencies]
 libc = "0.2"
diff --git a/src/tools/compiletest/src/common.rs b/src/tools/compiletest/src/common.rs
index 9e35d2b466763..36218b2f90457 100644
--- a/src/tools/compiletest/src/common.rs
+++ b/src/tools/compiletest/src/common.rs
@@ -275,9 +275,6 @@ pub struct Config {
     /// Explicitly enable or disable running.
     pub run: Option<bool>,
 
-    /// Write out a parseable log of tests that were run
-    pub logfile: Option<PathBuf>,
-
     /// A command line to prefix program execution with,
     /// for running under valgrind for example.
     ///
diff --git a/src/tools/compiletest/src/executor.rs b/src/tools/compiletest/src/executor.rs
index 7588fee2b2b06..527d6b8a36eb1 100644
--- a/src/tools/compiletest/src/executor.rs
+++ b/src/tools/compiletest/src/executor.rs
@@ -138,7 +138,7 @@ fn test_opts(config: &Config) -> test::TestOpts {
         filter_exact: config.filter_exact,
         run_ignored: if config.run_ignored { test::RunIgnored::Yes } else { test::RunIgnored::No },
         format: config.format.to_libtest(),
-        logfile: config.logfile.clone(),
+        logfile: None,
         run_tests: true,
         bench_benchmarks: true,
         nocapture: config.nocapture,
diff --git a/src/tools/compiletest/src/lib.rs b/src/tools/compiletest/src/lib.rs
index 8145ae1c1bced..782f6e0f2d8d2 100644
--- a/src/tools/compiletest/src/lib.rs
+++ b/src/tools/compiletest/src/lib.rs
@@ -139,7 +139,6 @@ pub fn parse_config(args: Vec<String>) -> Config {
         .optflag("", "quiet", "print one character per test instead of one line")
         .optopt("", "color", "coloring: auto, always, never", "WHEN")
         .optflag("", "json", "emit json output instead of plaintext output")
-        .optopt("", "logfile", "file to log test execution to", "FILE")
         .optopt("", "target", "the target to build for", "TARGET")
         .optopt("", "host", "the host to build for", "HOST")
         .optopt("", "cdb", "path to CDB to use for CDB debuginfo tests", "PATH")
@@ -378,7 +377,6 @@ pub fn parse_config(args: Vec<String>) -> Config {
             "never" => Some(false),
             _ => panic!("unknown `--run` option `{}` given", mode),
         }),
-        logfile: matches.opt_str("logfile").map(|s| PathBuf::from(&s)),
         runner: matches.opt_str("runner"),
         host_rustcflags: matches.opt_strs("host-rustcflags"),
         target_rustcflags: matches.opt_strs("target-rustcflags"),
diff --git a/src/tools/compiletest/src/runtest.rs b/src/tools/compiletest/src/runtest.rs
index c8a60b68da8b2..6446f9b11ae76 100644
--- a/src/tools/compiletest/src/runtest.rs
+++ b/src/tools/compiletest/src/runtest.rs
@@ -10,7 +10,6 @@ use std::process::{Child, Command, ExitStatus, Output, Stdio};
 use std::sync::Arc;
 use std::{env, iter, str};
 
-use anyhow::Context;
 use colored::Colorize;
 use regex::{Captures, Regex};
 use tracing::*;
@@ -143,11 +142,11 @@ pub fn run(config: Arc<Config>, testpaths: &TestPaths, revision: Option<&str>) {
     }
 
     let cx = TestCx { config: &config, props: &props, testpaths, revision };
-    create_dir_all(&cx.output_base_dir())
-        .with_context(|| {
-            format!("failed to create output base directory {}", cx.output_base_dir().display())
-        })
-        .unwrap();
+
+    if let Err(e) = create_dir_all(&cx.output_base_dir()) {
+        panic!("failed to create output base directory {}: {e}", cx.output_base_dir().display());
+    }
+
     if props.incremental {
         cx.init_incremental_test();
     }
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
index e4c50f2ebdb44..cc02b71f05c19 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/lib.rs
@@ -400,6 +400,7 @@ pub enum FnAbi {
     Rust,
     RustCall,
     RustCold,
+    RustIntrinsic,
     Stdcall,
     StdcallUnwind,
     System,
@@ -456,6 +457,7 @@ impl FnAbi {
             s if *s == sym::riscv_dash_interrupt_dash_s => FnAbi::RiscvInterruptS,
             s if *s == sym::rust_dash_call => FnAbi::RustCall,
             s if *s == sym::rust_dash_cold => FnAbi::RustCold,
+            s if *s == sym::rust_dash_intrinsic => FnAbi::RustIntrinsic,
             s if *s == sym::Rust => FnAbi::Rust,
             s if *s == sym::stdcall_dash_unwind => FnAbi::StdcallUnwind,
             s if *s == sym::stdcall => FnAbi::Stdcall,
@@ -498,6 +500,7 @@ impl FnAbi {
             FnAbi::Rust => "Rust",
             FnAbi::RustCall => "rust-call",
             FnAbi::RustCold => "rust-cold",
+            FnAbi::RustIntrinsic => "rust-intrinsic",
             FnAbi::Stdcall => "stdcall",
             FnAbi::StdcallUnwind => "stdcall-unwind",
             FnAbi::System => "system",
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs b/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs
index 06ac5b1ffad90..f61ecabb7e41d 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/mir/eval/shim.rs
@@ -59,7 +59,19 @@ impl Evaluator<'_> {
 
         let function_data = self.db.function_data(def);
         let attrs = self.db.attrs(def.into());
-        let is_intrinsic = attrs.by_key(&sym::rustc_intrinsic).exists();
+        let is_intrinsic = attrs.by_key(&sym::rustc_intrinsic).exists()
+            // Keep this around for a bit until extern "rustc-intrinsic" abis are no longer used
+            || (match &function_data.abi {
+                Some(abi) => *abi == sym::rust_dash_intrinsic,
+                None => match def.lookup(self.db.upcast()).container {
+                    hir_def::ItemContainerId::ExternBlockId(block) => {
+                        let id = block.lookup(self.db.upcast()).id;
+                        id.item_tree(self.db.upcast())[id.value].abi.as_ref()
+                            == Some(&sym::rust_dash_intrinsic)
+                    }
+                    _ => false,
+                },
+            });
 
         if is_intrinsic {
             return self.exec_intrinsic(
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/utils.rs b/src/tools/rust-analyzer/crates/hir-ty/src/utils.rs
index 0cfd36d9166b8..89d89fe2230af 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/utils.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/utils.rs
@@ -18,6 +18,7 @@ use hir_def::{
     TypeOrConstParamId,
 };
 use hir_expand::name::Name;
+use intern::sym;
 use rustc_abi::TargetDataLayout;
 use rustc_hash::FxHashSet;
 use smallvec::{smallvec, SmallVec};
@@ -302,13 +303,26 @@ pub fn is_fn_unsafe_to_call(
 
     let loc = func.lookup(db.upcast());
     match loc.container {
-        hir_def::ItemContainerId::ExternBlockId(_block) => {
-            // Function in an `extern` block are always unsafe to call, except when
-            // it is marked as `safe`.
-            if data.is_safe() {
-                Unsafety::Safe
+        hir_def::ItemContainerId::ExternBlockId(block) => {
+            let id = block.lookup(db.upcast()).id;
+            let is_intrinsic_block =
+                id.item_tree(db.upcast())[id.value].abi.as_ref() == Some(&sym::rust_dash_intrinsic);
+            if is_intrinsic_block {
+                // legacy intrinsics
+                // extern "rust-intrinsic" intrinsics are unsafe unless they have the rustc_safe_intrinsic attribute
+                if db.attrs(func.into()).by_key(&sym::rustc_safe_intrinsic).exists() {
+                    Unsafety::Safe
+                } else {
+                    Unsafety::Unsafe
+                }
             } else {
-                Unsafety::Unsafe
+                // Function in an `extern` block are always unsafe to call, except when
+                // it is marked as `safe`.
+                if data.is_safe() {
+                    Unsafety::Safe
+                } else {
+                    Unsafety::Unsafe
+                }
             }
         }
         _ => Unsafety::Safe,
diff --git a/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs b/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs
index a3554114f4c36..7c2cc2a6c1d8f 100644
--- a/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs
+++ b/src/tools/rust-analyzer/crates/ide-completion/src/completions/extern_abi.rs
@@ -36,6 +36,7 @@ const SUPPORTED_CALLING_CONVENTIONS: &[&str] = &[
     "wasm",
     "system",
     "system-unwind",
+    "rust-intrinsic",
     "rust-call",
     "unadjusted",
 ];
diff --git a/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs b/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs
index d4f334289f034..6b77c72cee897 100644
--- a/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs
+++ b/src/tools/rust-analyzer/crates/intern/src/symbol/symbols.rs
@@ -125,6 +125,7 @@ define_symbols! {
     riscv_dash_interrupt_dash_s = "riscv-interrupt-s",
     rust_dash_call = "rust-call",
     rust_dash_cold = "rust-cold",
+    rust_dash_intrinsic = "rust-intrinsic",
     stdcall_dash_unwind = "stdcall-unwind",
     system_dash_unwind = "system-unwind",
     sysv64_dash_unwind = "sysv64-unwind",
diff --git a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-62529-3.stderr b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-62529-3.stderr
index 64707642eeb01..36264b0d997b2 100644
--- a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-62529-3.stderr
+++ b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-62529-3.stderr
@@ -6,8 +6,8 @@ LL |         call(f, ());
    |         |
    |         required by a bound introduced by this call
    |
-   = note: expected a closure with arguments `((),)`
-              found a closure with arguments `(<_ as ATC<'a>>::Type,)`
+   = note: expected a closure with signature `for<'a> fn(<_ as ATC<'a>>::Type)`
+              found a closure with signature `fn(())`
 note: this is a known limitation of the trait solver that will be lifted in the future
   --> $DIR/issue-62529-3.rs:25:14
    |
diff --git a/tests/ui/implied-bounds/issue-100690.stderr b/tests/ui/implied-bounds/issue-100690.stderr
index 4964dccd551d9..d00895d8fc9cc 100644
--- a/tests/ui/implied-bounds/issue-100690.stderr
+++ b/tests/ui/implied-bounds/issue-100690.stderr
@@ -6,8 +6,8 @@ LL |         real_dispatch(f)
    |         |
    |         required by a bound introduced by this call
    |
-   = note: expected a closure with arguments `(&mut UIView<'a, _>,)`
-              found a closure with arguments `(&mut UIView<'_, _>,)`
+   = note: expected a closure with signature `for<'a, 'b> fn(&'a mut UIView<'b, _>)`
+              found a closure with signature `fn(&mut UIView<'a, _>)`
 note: required by a bound in `real_dispatch`
   --> $DIR/issue-100690.rs:8:8
    |
diff --git a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr
index b716131061993..7912ed4d7071a 100644
--- a/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr
+++ b/tests/ui/mismatched_types/closure-arg-type-mismatch-issue-45727.next.stderr
@@ -7,8 +7,8 @@ LL |     let _ = (-10..=10).find(|x: i32| x.signum() == 0);
    |                        required by a bound introduced by this call
    |
    = help: the trait `for<'a> FnMut(&'a <std::ops::RangeInclusive<{integer}> as Iterator>::Item)` is not implemented for closure `{closure@$DIR/closure-arg-type-mismatch-issue-45727.rs:6:29: 6:37}`
-   = note: expected a closure with arguments `(i32,)`
-              found a closure with arguments `(&<std::ops::RangeInclusive<{integer}> as Iterator>::Item,)`
+   = note: expected a closure with signature `for<'a> fn(&'a <std::ops::RangeInclusive<{integer}> as Iterator>::Item)`
+              found a closure with signature `fn(i32)`
 note: required by a bound in `find`
   --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
 
@@ -27,8 +27,8 @@ LL |     let _ = (-10..=10).find(|x: &&&i32| x.signum() == 0);
    |                        required by a bound introduced by this call
    |
    = help: the trait `for<'a> FnMut(&'a <std::ops::RangeInclusive<{integer}> as Iterator>::Item)` is not implemented for closure `{closure@$DIR/closure-arg-type-mismatch-issue-45727.rs:9:29: 9:40}`
-   = note: expected a closure with arguments `(&&&i32,)`
-              found a closure with arguments `(&<std::ops::RangeInclusive<{integer}> as Iterator>::Item,)`
+   = note: expected a closure with signature `for<'a> fn(&'a <std::ops::RangeInclusive<{integer}> as Iterator>::Item)`
+              found a closure with signature `fn(&&&i32)`
 note: required by a bound in `find`
   --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
 
diff --git a/tests/ui/trait-bounds/mismatch-fn-trait.stderr b/tests/ui/trait-bounds/mismatch-fn-trait.stderr
index 519aa9ea3f3bc..051e660c2d106 100644
--- a/tests/ui/trait-bounds/mismatch-fn-trait.stderr
+++ b/tests/ui/trait-bounds/mismatch-fn-trait.stderr
@@ -6,8 +6,8 @@ LL |     take(f)
    |     |
    |     required by a bound introduced by this call
    |
-   = note: expected a closure with arguments `(u32,)`
-              found a closure with arguments `(i32,)`
+   = note: expected a closure with signature `fn(i32)`
+              found a closure with signature `fn(u32)`
 note: required by a bound in `take`
   --> $DIR/mismatch-fn-trait.rs:1:18
    |
@@ -68,8 +68,8 @@ LL |     take(f)
    |     required by a bound introduced by this call
    |
    = note: `impl FnOnce(u32)` implements `FnOnce`, but it must implement `FnMut`, which is more general
-   = note: expected a closure with arguments `(u32,)`
-              found a closure with arguments `(i32,)`
+   = note: expected a closure with signature `fn(i32)`
+              found a closure with signature `fn(u32)`
 note: required by a bound in `take`
   --> $DIR/mismatch-fn-trait.rs:1:18
    |
diff --git a/tests/ui/transmutability/transmute-higher-ranked.rs b/tests/ui/transmutability/transmute-higher-ranked.rs
new file mode 100644
index 0000000000000..f0fe02a7908ee
--- /dev/null
+++ b/tests/ui/transmutability/transmute-higher-ranked.rs
@@ -0,0 +1,18 @@
+// Ensure we don't ICE when transmuting higher-ranked types via a
+// higher-ranked transmute goal.
+
+//@ check-pass
+
+#![feature(transmutability)]
+
+use std::mem::TransmuteFrom;
+
+pub fn transmute()
+where
+    for<'a> &'a &'a i32: TransmuteFrom<&'a &'a u32>,
+{
+}
+
+fn main() {
+    transmute();
+}