diff --git a/compiler/rustc_abi/src/layout.rs b/compiler/rustc_abi/src/layout.rs
index 28e148bddb220..1c6d0495ecfa1 100644
--- a/compiler/rustc_abi/src/layout.rs
+++ b/compiler/rustc_abi/src/layout.rs
@@ -1,6 +1,9 @@
+use std::borrow::{Borrow, Cow};
+use std::cmp;
 use std::fmt::{self, Write};
+use std::iter;
+use std::ops::Bound;
 use std::ops::Deref;
-use std::{borrow::Borrow, cmp, iter, ops::Bound};
 
 use rustc_index::Idx;
 use tracing::debug;
@@ -32,7 +35,7 @@ where
 pub trait LayoutCalculator {
     type TargetDataLayoutRef: Borrow<TargetDataLayout>;
 
-    fn delayed_bug(&self, txt: String);
+    fn delayed_bug(&self, txt: impl Into<Cow<'static, str>>);
     fn current_data_layout(&self) -> Self::TargetDataLayoutRef;
 
     fn scalar_pair<FieldIdx: Idx, VariantIdx: Idx>(
diff --git a/compiler/rustc_ast_lowering/src/asm.rs b/compiler/rustc_ast_lowering/src/asm.rs
index fd717e82d26df..7fd419f62e459 100644
--- a/compiler/rustc_ast_lowering/src/asm.rs
+++ b/compiler/rustc_ast_lowering/src/asm.rs
@@ -22,6 +22,7 @@ use std::collections::hash_map::Entry;
 use std::fmt::Write;
 
 impl<'a, 'hir> LoweringContext<'a, 'hir> {
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     pub(crate) fn lower_inline_asm(
         &mut self,
         sp: Span,
diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index 85b599902b959..41f7418ddde42 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -1513,6 +1513,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn lower_expr_yield(&mut self, span: Span, opt_expr: Option<&Expr>) -> hir::ExprKind<'hir> {
         let yielded =
             opt_expr.as_ref().map(|x| self.lower_expr(x)).unwrap_or_else(|| self.expr_unit(span));
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index 087d240b0d50f..37ee9a5140a06 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -2272,6 +2272,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         self.expr_block(block)
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn lower_array_length(&mut self, c: &AnonConst) -> hir::ArrayLen {
         match c.value.kind {
             ExprKind::Underscore => {
diff --git a/compiler/rustc_ast_passes/src/feature_gate.rs b/compiler/rustc_ast_passes/src/feature_gate.rs
index a28fcb0077948..d9e3f028697e0 100644
--- a/compiler/rustc_ast_passes/src/feature_gate.rs
+++ b/compiler/rustc_ast_passes/src/feature_gate.rs
@@ -17,6 +17,7 @@ use crate::errors;
 macro_rules! gate {
     ($visitor:expr, $feature:ident, $span:expr, $explain:expr) => {{
         if !$visitor.features.$feature && !$span.allows_unstable(sym::$feature) {
+            #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
             feature_err(&$visitor.sess, sym::$feature, $span, $explain).emit();
         }
     }};
@@ -34,6 +35,7 @@ macro_rules! gate {
 macro_rules! gate_alt {
     ($visitor:expr, $has_feature:expr, $name:expr, $span:expr, $explain:expr) => {{
         if !$has_feature && !$span.allows_unstable($name) {
+            #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
             feature_err(&$visitor.sess, $name, $span, $explain).emit();
         }
     }};
@@ -73,6 +75,7 @@ struct PostExpansionVisitor<'a> {
 }
 
 impl<'a> PostExpansionVisitor<'a> {
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_abi(&self, abi: ast::StrLit, constness: ast::Const) {
         let ast::StrLit { symbol_unescaped, span, .. } = abi;
 
@@ -579,6 +582,7 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session, features: &Features) {
                 if let Ok(snippet) = sm.span_to_snippet(span)
                     && snippet == "!"
                 {
+                    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
                     feature_err(sess, sym::never_patterns, span, "`!` patterns are experimental")
                         .emit();
                 } else {
diff --git a/compiler/rustc_attr/src/builtin.rs b/compiler/rustc_attr/src/builtin.rs
index eb25b910c7baf..814104ec78c49 100644
--- a/compiler/rustc_attr/src/builtin.rs
+++ b/compiler/rustc_attr/src/builtin.rs
@@ -516,6 +516,7 @@ pub struct Condition {
 }
 
 /// Tests if a cfg-pattern matches the cfg set
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn cfg_matches(
     cfg: &ast::MetaItem,
     sess: &Session,
@@ -566,6 +567,7 @@ fn try_gate_cfg(name: Symbol, span: Span, sess: &Session, features: Option<&Feat
     }
 }
 
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 fn gate_cfg(gated_cfg: &GatedCfg, cfg_span: Span, sess: &Session, features: &Features) {
     let (cfg, feature, has_feature) = gated_cfg;
     if !has_feature(features) && !cfg_span.allows_unstable(*feature) {
@@ -592,6 +594,7 @@ fn parse_version(s: Symbol) -> Option<RustcVersion> {
 
 /// Evaluate a cfg-like condition (with `any` and `all`), using `eval` to
 /// evaluate individual items.
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn eval_condition(
     cfg: &ast::MetaItem,
     sess: &Session,
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index 53e8ac121bbce..560928d394145 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -76,6 +76,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
     /// LL |         for (key, value) in dict {
     ///    |                             ^^^^
     /// ```
+    #[allow(rustc::diagnostic_outside_of_impl)] // FIXME
     pub(super) fn add_moved_or_invoked_closure_note(
         &self,
         location: Location,
@@ -585,6 +586,7 @@ impl UseSpans<'_> {
     }
 
     /// Add a span label to the arguments of the closure, if it exists.
+    #[allow(rustc::diagnostic_outside_of_impl)]
     pub(super) fn args_subdiag(
         self,
         dcx: &rustc_errors::DiagCtxt,
@@ -598,6 +600,7 @@ impl UseSpans<'_> {
 
     /// Add a span label to the use of the captured variable, if it exists.
     /// only adds label to the `path_span`
+    #[allow(rustc::diagnostic_outside_of_impl)]
     pub(super) fn var_path_only_subdiag(
         self,
         dcx: &rustc_errors::DiagCtxt,
@@ -635,6 +638,7 @@ impl UseSpans<'_> {
     }
 
     /// Add a subdiagnostic to the use of the captured variable, if it exists.
+    #[allow(rustc::diagnostic_outside_of_impl)]
     pub(super) fn var_subdiag(
         self,
         dcx: &rustc_errors::DiagCtxt,
@@ -1008,6 +1012,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         self.borrow_spans(span, borrow.reserve_location)
     }
 
+    #[allow(rustc::diagnostic_outside_of_impl)]
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn explain_captures(
         &mut self,
         err: &mut Diag<'_>,
diff --git a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
index 3765dfe5db53c..c06bf94a6fd5f 100644
--- a/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/region_errors.rs
@@ -201,6 +201,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     // For generic associated types (GATs) which implied 'static requirement
     // from higher-ranked trait bounds (HRTB). Try to locate span of the trait
     // and the span which bounded to the trait for adding 'static lifetime suggestion
+    #[allow(rustc::diagnostic_outside_of_impl)]
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn suggest_static_lifetime_for_gat_from_hrtb(
         &self,
         diag: &mut Diag<'_>,
@@ -254,9 +256,6 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
 
         hrtb_bounds.iter().for_each(|bound| {
             let Trait(PolyTraitRef { trait_ref, span: trait_span, .. }, _) = bound else { return; };
-            // FIXME: make this translatable
-            #[allow(rustc::diagnostic_outside_of_impl)]
-            #[allow(rustc::untranslatable_diagnostic)]
             diag.span_note(
                 *trait_span,
                 "due to current limitations in the borrow checker, this implies a `'static` lifetime"
@@ -580,6 +579,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     ///            executing...
     ///    = note: ...therefore, returned references to captured variables will escape the closure
     /// ```
+    #[allow(rustc::diagnostic_outside_of_impl)] // FIXME
     fn report_fnmut_error(
         &self,
         errci: &ErrorConstraintInfo<'tcx>,
@@ -761,6 +761,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     ///    |     ^^^^^^^^^^^^^^ function was supposed to return data with lifetime `'a` but it
     ///    |                    is returning data with lifetime `'b`
     /// ```
+    #[allow(rustc::diagnostic_outside_of_impl)] // FIXME
     fn report_general_error(&self, errci: &ErrorConstraintInfo<'tcx>) -> Diag<'tcx> {
         let ErrorConstraintInfo {
             fr,
@@ -822,6 +823,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
     /// LL |     fn iter_values_anon(&self) -> impl Iterator<Item=u32> + 'a {
     ///    |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
     /// ```
+    #[allow(rustc::diagnostic_outside_of_impl)]
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn add_static_impl_trait_suggestion(
         &self,
         diag: &mut Diag<'_>,
@@ -972,6 +975,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         self.suggest_constrain_dyn_trait_in_impl(diag, &visitor.0, ident, self_ty);
     }
 
+    #[allow(rustc::diagnostic_outside_of_impl)]
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     #[instrument(skip(self, err), level = "debug")]
     fn suggest_constrain_dyn_trait_in_impl(
         &self,
@@ -1034,6 +1039,8 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         suggest_adding_lifetime_params(self.infcx.tcx, sub, ty_sup, ty_sub, diag);
     }
 
+    #[allow(rustc::diagnostic_outside_of_impl)]
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn suggest_move_on_borrowing_closure(&self, diag: &mut Diag<'_>) {
         let map = self.infcx.tcx.hir();
         let body_id = map.body_owned_by(self.mir_def_id());
diff --git a/compiler/rustc_builtin_macros/src/source_util.rs b/compiler/rustc_builtin_macros/src/source_util.rs
index 2da9bda19e034..134a6baea6e8b 100644
--- a/compiler/rustc_builtin_macros/src/source_util.rs
+++ b/compiler/rustc_builtin_macros/src/source_util.rs
@@ -3,18 +3,20 @@ use rustc_ast::ptr::P;
 use rustc_ast::token;
 use rustc_ast::tokenstream::TokenStream;
 use rustc_ast_pretty::pprust;
+use rustc_data_structures::sync::Lrc;
 use rustc_expand::base::{
-    check_zero_tts, get_single_str_from_tts, parse_expr, resolve_path, DummyResult, ExtCtxt,
-    MacEager, MacResult,
+    check_zero_tts, get_single_str_from_tts, get_single_str_spanned_from_tts, parse_expr,
+    resolve_path, DummyResult, ExtCtxt, MacEager, MacResult,
 };
 use rustc_expand::module::DirOwnership;
 use rustc_parse::new_parser_from_file;
 use rustc_parse::parser::{ForceCollect, Parser};
 use rustc_session::lint::builtin::INCOMPLETE_INCLUDE;
+use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::Symbol;
 use rustc_span::{Pos, Span};
-
 use smallvec::SmallVec;
+use std::path::{Path, PathBuf};
 use std::rc::Rc;
 
 // These macros all relate to the file system; they either return
@@ -180,32 +182,22 @@ pub fn expand_include_str(
     tts: TokenStream,
 ) -> Box<dyn MacResult + 'static> {
     let sp = cx.with_def_site_ctxt(sp);
-    let file = match get_single_str_from_tts(cx, sp, tts, "include_str!") {
-        Ok(file) => file,
+    let (path, path_span) = match get_single_str_spanned_from_tts(cx, sp, tts, "include_str!") {
+        Ok(res) => res,
         Err(guar) => return DummyResult::any(sp, guar),
     };
-    let file = match resolve_path(&cx.sess, file.as_str(), sp) {
-        Ok(f) => f,
-        Err(err) => {
-            let guar = err.emit();
-            return DummyResult::any(sp, guar);
-        }
-    };
-    match cx.source_map().load_binary_file(&file) {
+    match load_binary_file(cx, path.as_str().as_ref(), sp, path_span) {
         Ok(bytes) => match std::str::from_utf8(&bytes) {
             Ok(src) => {
                 let interned_src = Symbol::intern(src);
                 MacEager::expr(cx.expr_str(sp, interned_src))
             }
             Err(_) => {
-                let guar = cx.dcx().span_err(sp, format!("{} wasn't a utf-8 file", file.display()));
+                let guar = cx.dcx().span_err(sp, format!("`{path}` wasn't a utf-8 file"));
                 DummyResult::any(sp, guar)
             }
         },
-        Err(e) => {
-            let guar = cx.dcx().span_err(sp, format!("couldn't read {}: {}", file.display(), e));
-            DummyResult::any(sp, guar)
-        }
+        Err(dummy) => dummy,
     }
 }
 
@@ -215,25 +207,123 @@ pub fn expand_include_bytes(
     tts: TokenStream,
 ) -> Box<dyn MacResult + 'static> {
     let sp = cx.with_def_site_ctxt(sp);
-    let file = match get_single_str_from_tts(cx, sp, tts, "include_bytes!") {
-        Ok(file) => file,
+    let (path, path_span) = match get_single_str_spanned_from_tts(cx, sp, tts, "include_bytes!") {
+        Ok(res) => res,
         Err(guar) => return DummyResult::any(sp, guar),
     };
-    let file = match resolve_path(&cx.sess, file.as_str(), sp) {
-        Ok(f) => f,
+    match load_binary_file(cx, path.as_str().as_ref(), sp, path_span) {
+        Ok(bytes) => {
+            let expr = cx.expr(sp, ast::ExprKind::IncludedBytes(bytes));
+            MacEager::expr(expr)
+        }
+        Err(dummy) => dummy,
+    }
+}
+
+fn load_binary_file(
+    cx: &mut ExtCtxt<'_>,
+    original_path: &Path,
+    macro_span: Span,
+    path_span: Span,
+) -> Result<Lrc<[u8]>, Box<dyn MacResult>> {
+    let resolved_path = match resolve_path(&cx.sess, original_path, macro_span) {
+        Ok(path) => path,
         Err(err) => {
             let guar = err.emit();
-            return DummyResult::any(sp, guar);
+            return Err(DummyResult::any(macro_span, guar));
         }
     };
-    match cx.source_map().load_binary_file(&file) {
-        Ok(bytes) => {
-            let expr = cx.expr(sp, ast::ExprKind::IncludedBytes(bytes));
-            MacEager::expr(expr)
+    match cx.source_map().load_binary_file(&resolved_path) {
+        Ok(data) => Ok(data),
+        Err(io_err) => {
+            let mut err = cx.dcx().struct_span_err(
+                macro_span,
+                format!("couldn't read `{}`: {io_err}", resolved_path.display()),
+            );
+
+            if original_path.is_relative() {
+                let source_map = cx.sess.source_map();
+                let new_path = source_map
+                    .span_to_filename(macro_span.source_callsite())
+                    .into_local_path()
+                    .and_then(|src| find_path_suggestion(source_map, src.parent()?, original_path))
+                    .and_then(|path| path.into_os_string().into_string().ok());
+
+                if let Some(new_path) = new_path {
+                    err.span_suggestion(
+                        path_span,
+                        "there is a file with the same name in a different directory",
+                        format!("\"{}\"", new_path.escape_debug()),
+                        rustc_lint_defs::Applicability::MachineApplicable,
+                    );
+                }
+            }
+            let guar = err.emit();
+            Err(DummyResult::any(macro_span, guar))
         }
-        Err(e) => {
-            let guar = cx.dcx().span_err(sp, format!("couldn't read {}: {}", file.display(), e));
-            DummyResult::any(sp, guar)
+    }
+}
+
+fn find_path_suggestion(
+    source_map: &SourceMap,
+    base_dir: &Path,
+    wanted_path: &Path,
+) -> Option<PathBuf> {
+    // Fix paths that assume they're relative to cargo manifest dir
+    let mut base_c = base_dir.components();
+    let mut wanted_c = wanted_path.components();
+    let mut without_base = None;
+    while let Some(wanted_next) = wanted_c.next() {
+        if wanted_c.as_path().file_name().is_none() {
+            break;
+        }
+        // base_dir may be absolute
+        while let Some(base_next) = base_c.next() {
+            if base_next == wanted_next {
+                without_base = Some(wanted_c.as_path());
+                break;
+            }
+        }
+    }
+    let root_absolute = without_base.into_iter().map(PathBuf::from);
+
+    let base_dir_components = base_dir.components().count();
+    // Avoid going all the way to the root dir
+    let max_parent_components = if base_dir.is_relative() {
+        base_dir_components + 1
+    } else {
+        base_dir_components.saturating_sub(1)
+    };
+
+    // Try with additional leading ../
+    let mut prefix = PathBuf::new();
+    let add = std::iter::from_fn(|| {
+        prefix.push("..");
+        Some(prefix.join(wanted_path))
+    })
+    .take(max_parent_components.min(3));
+
+    // Try without leading directories
+    let mut trimmed_path = wanted_path;
+    let remove = std::iter::from_fn(|| {
+        let mut components = trimmed_path.components();
+        let removed = components.next()?;
+        trimmed_path = components.as_path();
+        let _ = trimmed_path.file_name()?; // ensure there is a file name left
+        Some([
+            Some(trimmed_path.to_path_buf()),
+            (removed != std::path::Component::ParentDir)
+                .then(|| Path::new("..").join(trimmed_path)),
+        ])
+    })
+    .flatten()
+    .flatten()
+    .take(4);
+
+    for new_path in root_absolute.chain(add).chain(remove) {
+        if source_map.file_exists(&base_dir.join(&new_path)) {
+            return Some(new_path);
         }
     }
+    None
 }
diff --git a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
index f7ff36c0467d2..9ae82d4845e16 100644
--- a/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/rvalue.rs
@@ -94,8 +94,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 }
 
                 if let OperandValue::Immediate(v) = cg_elem.val {
-                    let zero = bx.const_usize(0);
-                    let start = dest.project_index(bx, zero).llval;
+                    let start = dest.llval;
                     let size = bx.const_usize(dest.layout.size.bytes());
 
                     // Use llvm.memset.p0i8.* to initialize all zero arrays
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/ops.rs b/compiler/rustc_const_eval/src/transform/check_consts/ops.rs
index 1107b894ab3ee..15720f25c5cff 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/ops.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/ops.rs
@@ -62,6 +62,7 @@ impl<'tcx> NonConstOp<'tcx> for FloatingPointOp {
         }
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> Diag<'tcx> {
         feature_err(
             &ccx.tcx.sess,
@@ -556,6 +557,7 @@ impl<'tcx> NonConstOp<'tcx> for RawMutPtrDeref {
         Status::Unstable(sym::const_mut_refs)
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> Diag<'tcx> {
         feature_err(
             &ccx.tcx.sess,
@@ -589,6 +591,7 @@ impl<'tcx> NonConstOp<'tcx> for StaticAccess {
         }
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> Diag<'tcx> {
         let mut err = feature_err(
             &ccx.tcx.sess,
@@ -632,6 +635,7 @@ pub mod ty {
             }
         }
 
+        #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
         fn build_error(&self, ccx: &ConstCx<'_, 'tcx>, span: Span) -> Diag<'tcx> {
             feature_err(
                 &ccx.tcx.sess,
diff --git a/compiler/rustc_driver_impl/src/args.rs b/compiler/rustc_driver_impl/src/args.rs
index 5dfd37a6da4de..8b6fb5fd660f3 100644
--- a/compiler/rustc_driver_impl/src/args.rs
+++ b/compiler/rustc_driver_impl/src/args.rs
@@ -97,6 +97,7 @@ impl Expander {
 /// **Note:** This function doesn't interpret argument 0 in any special way.
 /// If this function is intended to be used with command line arguments,
 /// `argv[0]` must be removed prior to calling it manually.
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn arg_expand_all(early_dcx: &EarlyDiagCtxt, at_args: &[String]) -> Vec<String> {
     let mut expander = Expander::default();
     for arg in at_args {
diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 85be97ea24fdf..3b6bf0005a3b1 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -4,6 +4,7 @@
 //!
 //! This API is completely unstable and subject to change.
 
+#![allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(rustdoc_internals)]
diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index 5390dda9b21ad..c186d5b284fc4 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -598,6 +598,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     ///
     /// In the meantime, though, callsites are required to deal with the "bug"
     /// locally in whichever way makes the most sense.
+    #[rustc_lint_diagnostics]
     #[track_caller]
     pub fn downgrade_to_delayed_bug(&mut self) {
         assert!(
@@ -631,6 +632,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     with_fn! { with_span_labels,
     /// Labels all the given spans with the provided label.
     /// See [`Self::span_label()`] for more information.
+    #[rustc_lint_diagnostics]
     pub fn span_labels(&mut self, spans: impl IntoIterator<Item = Span>, label: &str) -> &mut Self {
         for span in spans {
             self.span_label(span, label.to_string());
@@ -638,6 +640,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self
     } }
 
+    #[rustc_lint_diagnostics]
     pub fn replace_span_with(&mut self, after: Span, keep_label: bool) -> &mut Self {
         let before = self.span.clone();
         self.span(after);
@@ -653,6 +656,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self
     }
 
+    #[rustc_lint_diagnostics]
     pub fn note_expected_found(
         &mut self,
         expected_label: &dyn fmt::Display,
@@ -663,6 +667,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self.note_expected_found_extra(expected_label, expected, found_label, found, &"", &"")
     }
 
+    #[rustc_lint_diagnostics]
     pub fn note_expected_found_extra(
         &mut self,
         expected_label: &dyn fmt::Display,
@@ -705,6 +710,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self
     }
 
+    #[rustc_lint_diagnostics]
     pub fn note_trait_signature(&mut self, name: Symbol, signature: String) -> &mut Self {
         self.highlighted_note(vec![
             StringPart::normal(format!("`{name}` from trait: `")),
@@ -722,12 +728,14 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self
     } }
 
+    #[rustc_lint_diagnostics]
     fn highlighted_note(&mut self, msg: Vec<StringPart>) -> &mut Self {
         self.sub_with_highlights(Level::Note, msg, MultiSpan::new());
         self
     }
 
     /// This is like [`Diag::note()`], but it's only printed once.
+    #[rustc_lint_diagnostics]
     pub fn note_once(&mut self, msg: impl Into<SubdiagMessage>) -> &mut Self {
         self.sub(Level::OnceNote, msg, MultiSpan::new());
         self
@@ -748,6 +756,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     /// Prints the span with a note above it.
     /// This is like [`Diag::note_once()`], but it gets its own span.
+    #[rustc_lint_diagnostics]
     pub fn span_note_once<S: Into<MultiSpan>>(
         &mut self,
         sp: S,
@@ -786,12 +795,14 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     } }
 
     /// This is like [`Diag::help()`], but it's only printed once.
+    #[rustc_lint_diagnostics]
     pub fn help_once(&mut self, msg: impl Into<SubdiagMessage>) -> &mut Self {
         self.sub(Level::OnceHelp, msg, MultiSpan::new());
         self
     }
 
     /// Add a help message attached to this diagnostic with a customizable highlighted message.
+    #[rustc_lint_diagnostics]
     pub fn highlighted_help(&mut self, msg: Vec<StringPart>) -> &mut Self {
         self.sub_with_highlights(Level::Help, msg, MultiSpan::new());
         self
@@ -812,12 +823,14 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// Disallow attaching suggestions this diagnostic.
     /// Any suggestions attached e.g. with the `span_suggestion_*` methods
     /// (before and after the call to `disable_suggestions`) will be ignored.
+    #[rustc_lint_diagnostics]
     pub fn disable_suggestions(&mut self) -> &mut Self {
         self.suggestions = Err(SuggestionsDisabled);
         self
     }
 
     /// Helper for pushing to `self.suggestions`, if available (not disable).
+    #[rustc_lint_diagnostics]
     fn push_suggestion(&mut self, suggestion: CodeSuggestion) {
         for subst in &suggestion.substitutions {
             for part in &subst.parts {
@@ -838,6 +851,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     with_fn! { with_multipart_suggestion,
     /// Show a suggestion that has multiple parts to it.
     /// In other words, multiple changes need to be applied as part of this suggestion.
+    #[rustc_lint_diagnostics]
     pub fn multipart_suggestion(
         &mut self,
         msg: impl Into<SubdiagMessage>,
@@ -854,6 +868,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     /// Show a suggestion that has multiple parts to it, always as it's own subdiagnostic.
     /// In other words, multiple changes need to be applied as part of this suggestion.
+    #[rustc_lint_diagnostics]
     pub fn multipart_suggestion_verbose(
         &mut self,
         msg: impl Into<SubdiagMessage>,
@@ -869,6 +884,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     }
 
     /// [`Diag::multipart_suggestion()`] but you can set the [`SuggestionStyle`].
+    #[rustc_lint_diagnostics]
     pub fn multipart_suggestion_with_style(
         &mut self,
         msg: impl Into<SubdiagMessage>,
@@ -911,6 +927,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// be from the message, showing the span label inline would be visually unpleasant
     /// (marginally overlapping spans or multiline spans) and showing the snippet window wouldn't
     /// improve understandability.
+    #[rustc_lint_diagnostics]
     pub fn tool_only_multipart_suggestion(
         &mut self,
         msg: impl Into<SubdiagMessage>,
@@ -943,6 +960,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// * may contain a name of a function, variable, or type, but not whole expressions
     ///
     /// See `CodeSuggestion` for more information.
+    #[rustc_lint_diagnostics]
     pub fn span_suggestion(
         &mut self,
         sp: Span,
@@ -961,6 +979,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     } }
 
     /// [`Diag::span_suggestion()`] but you can set the [`SuggestionStyle`].
+    #[rustc_lint_diagnostics]
     pub fn span_suggestion_with_style(
         &mut self,
         sp: Span,
@@ -986,6 +1005,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     with_fn! { with_span_suggestion_verbose,
     /// Always show the suggested change.
+    #[rustc_lint_diagnostics]
     pub fn span_suggestion_verbose(
         &mut self,
         sp: Span,
@@ -1006,6 +1026,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     with_fn! { with_span_suggestions,
     /// Prints out a message with multiple suggested edits of the code.
     /// See also [`Diag::span_suggestion()`].
+    #[rustc_lint_diagnostics]
     pub fn span_suggestions(
         &mut self,
         sp: Span,
@@ -1022,6 +1043,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         )
     } }
 
+    #[rustc_lint_diagnostics]
     pub fn span_suggestions_with_style(
         &mut self,
         sp: Span,
@@ -1052,6 +1074,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// Prints out a message with multiple suggested edits of the code, where each edit consists of
     /// multiple parts.
     /// See also [`Diag::multipart_suggestion()`].
+    #[rustc_lint_diagnostics]
     pub fn multipart_suggestions(
         &mut self,
         msg: impl Into<SubdiagMessage>,
@@ -1098,6 +1121,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// inline, it will only show the message and not the suggestion.
     ///
     /// See `CodeSuggestion` for more information.
+    #[rustc_lint_diagnostics]
     pub fn span_suggestion_short(
         &mut self,
         sp: Span,
@@ -1121,6 +1145,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// be from the message, showing the span label inline would be visually unpleasant
     /// (marginally overlapping spans or multiline spans) and showing the snippet window wouldn't
     /// improve understandability.
+    #[rustc_lint_diagnostics]
     pub fn span_suggestion_hidden(
         &mut self,
         sp: Span,
@@ -1165,6 +1190,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
     /// [rustc_macros::Subdiagnostic]). Performs eager translation of any translatable messages
     /// used in the subdiagnostic, so suitable for use with repeated messages (i.e. re-use of
     /// interpolated variables).
+    #[rustc_lint_diagnostics]
     pub fn subdiagnostic(
         &mut self,
         dcx: &crate::DiagCtxt,
@@ -1180,6 +1206,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     with_fn! { with_span,
     /// Add a span.
+    #[rustc_lint_diagnostics]
     pub fn span(&mut self, sp: impl Into<MultiSpan>) -> &mut Self {
         self.span = sp.into();
         if let Some(span) = self.span.primary_span() {
@@ -1188,6 +1215,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self
     } }
 
+    #[rustc_lint_diagnostics]
     pub fn is_lint(&mut self, name: String, has_future_breakage: bool) -> &mut Self {
         self.is_lint = Some(IsLint { name, has_future_breakage });
         self
@@ -1195,6 +1223,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     with_fn! { with_code,
     /// Add an error code.
+    #[rustc_lint_diagnostics]
     pub fn code(&mut self, code: ErrCode) -> &mut Self {
         self.code = Some(code);
         self
@@ -1202,6 +1231,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     with_fn! { with_primary_message,
     /// Add a primary message.
+    #[rustc_lint_diagnostics]
     pub fn primary_message(&mut self, msg: impl Into<DiagMessage>) -> &mut Self {
         self.messages[0] = (msg.into(), Style::NoStyle);
         self
@@ -1209,6 +1239,7 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
 
     with_fn! { with_arg,
     /// Add an argument.
+    #[rustc_lint_diagnostics]
     pub fn arg(
         &mut self,
         name: impl Into<DiagArgName>,
diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 0caa8fa9e8abe..76b44f73f47b8 100644
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -1101,32 +1101,36 @@ impl DiagCtxt {
 // Functions beginning with `struct_`/`create_` create a diagnostic. Other
 // functions create and emit a diagnostic all in one go.
 impl DiagCtxt {
-    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    // No `#[rustc_lint_diagnostics]` and no `impl Into<DiagMessage>` because bug messages aren't
+    // user-facing.
     #[track_caller]
-    pub fn struct_bug(&self, msg: impl Into<DiagMessage>) -> Diag<'_, BugAbort> {
-        Diag::new(self, Bug, msg)
+    pub fn struct_bug(&self, msg: impl Into<Cow<'static, str>>) -> Diag<'_, BugAbort> {
+        Diag::new(self, Bug, msg.into())
     }
 
-    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    // No `#[rustc_lint_diagnostics]` and no `impl Into<DiagMessage>` because bug messages aren't
+    // user-facing.
     #[track_caller]
-    pub fn bug(&self, msg: impl Into<DiagMessage>) -> ! {
+    pub fn bug(&self, msg: impl Into<Cow<'static, str>>) -> ! {
         self.struct_bug(msg).emit()
     }
 
-    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    // No `#[rustc_lint_diagnostics]` and no `impl Into<DiagMessage>` because bug messages aren't
+    // user-facing.
     #[track_caller]
     pub fn struct_span_bug(
         &self,
         span: impl Into<MultiSpan>,
-        msg: impl Into<DiagMessage>,
+        msg: impl Into<Cow<'static, str>>,
     ) -> Diag<'_, BugAbort> {
         self.struct_bug(msg).with_span(span)
     }
 
-    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    // No `#[rustc_lint_diagnostics]` and no `impl Into<DiagMessage>` because bug messages aren't
+    // user-facing.
     #[track_caller]
-    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagMessage>) -> ! {
-        self.struct_span_bug(span, msg).emit()
+    pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: impl Into<Cow<'static, str>>) -> ! {
+        self.struct_span_bug(span, msg.into()).emit()
     }
 
     #[track_caller]
@@ -1240,24 +1244,28 @@ impl DiagCtxt {
     }
 
     /// Ensures that an error is printed. See `Level::DelayedBug`.
-    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    //
+    // No `#[rustc_lint_diagnostics]` and no `impl Into<DiagMessage>` because bug messages aren't
+    // user-facing.
     #[track_caller]
-    pub fn delayed_bug(&self, msg: impl Into<DiagMessage>) -> ErrorGuaranteed {
-        Diag::<ErrorGuaranteed>::new(self, DelayedBug, msg).emit()
+    pub fn delayed_bug(&self, msg: impl Into<Cow<'static, str>>) -> ErrorGuaranteed {
+        Diag::<ErrorGuaranteed>::new(self, DelayedBug, msg.into()).emit()
     }
 
     /// Ensures that an error is printed. See `Level::DelayedBug`.
     ///
     /// Note: this function used to be called `delay_span_bug`. It was renamed
     /// to match similar functions like `span_err`, `span_warn`, etc.
-    // No `#[rustc_lint_diagnostics]` because bug messages aren't user-facing.
+    //
+    // No `#[rustc_lint_diagnostics]` and no `impl Into<DiagMessage>` because bug messages aren't
+    // user-facing.
     #[track_caller]
     pub fn span_delayed_bug(
         &self,
         sp: impl Into<MultiSpan>,
-        msg: impl Into<DiagMessage>,
+        msg: impl Into<Cow<'static, str>>,
     ) -> ErrorGuaranteed {
-        Diag::<ErrorGuaranteed>::new(self, DelayedBug, msg).with_span(sp).emit()
+        Diag::<ErrorGuaranteed>::new(self, DelayedBug, msg.into()).with_span(sp).emit()
     }
 
     #[rustc_lint_diagnostics]
diff --git a/compiler/rustc_expand/src/base.rs b/compiler/rustc_expand/src/base.rs
index 0beba2a550466..58589ebdca675 100644
--- a/compiler/rustc_expand/src/base.rs
+++ b/compiler/rustc_expand/src/base.rs
@@ -1233,21 +1233,18 @@ pub fn resolve_path(sess: &Session, path: impl Into<PathBuf>, span: Span) -> PRe
     // after macro expansion (that is, they are unhygienic).
     if !path.is_absolute() {
         let callsite = span.source_callsite();
-        let mut result = match sess.source_map().span_to_filename(callsite) {
-            FileName::Real(name) => name
-                .into_local_path()
-                .expect("attempting to resolve a file path in an external file"),
-            FileName::DocTest(path, _) => path,
-            other => {
-                return Err(sess.dcx().create_err(errors::ResolveRelativePath {
-                    span,
-                    path: sess.source_map().filename_for_diagnostics(&other).to_string(),
-                }));
-            }
+        let source_map = sess.source_map();
+        let Some(mut base_path) = source_map.span_to_filename(callsite).into_local_path() else {
+            return Err(sess.dcx().create_err(errors::ResolveRelativePath {
+                span,
+                path: source_map
+                    .filename_for_diagnostics(&source_map.span_to_filename(callsite))
+                    .to_string(),
+            }));
         };
-        result.pop();
-        result.push(path);
-        Ok(result)
+        base_path.pop();
+        base_path.push(path);
+        Ok(base_path)
     } else {
         Ok(path)
     }
@@ -1344,6 +1341,15 @@ pub fn get_single_str_from_tts(
     tts: TokenStream,
     name: &str,
 ) -> Result<Symbol, ErrorGuaranteed> {
+    get_single_str_spanned_from_tts(cx, span, tts, name).map(|(s, _)| s)
+}
+
+pub fn get_single_str_spanned_from_tts(
+    cx: &mut ExtCtxt<'_>,
+    span: Span,
+    tts: TokenStream,
+    name: &str,
+) -> Result<(Symbol, Span), ErrorGuaranteed> {
     let mut p = cx.new_parser_from_tts(tts);
     if p.token == token::Eof {
         let guar = cx.dcx().emit_err(errors::OnlyOneArgument { span, name });
@@ -1355,7 +1361,12 @@ pub fn get_single_str_from_tts(
     if p.token != token::Eof {
         cx.dcx().emit_err(errors::OnlyOneArgument { span, name });
     }
-    expr_to_string(cx, ret, "argument must be a string literal").map(|(s, _)| s)
+    expr_to_spanned_string(cx, ret, "argument must be a string literal")
+        .map_err(|err| match err {
+            Ok((err, _)) => err.emit(),
+            Err(guar) => guar,
+        })
+        .map(|(symbol, _style, span)| (symbol, span))
 }
 
 /// Extracts comma-separated expressions from `tts`.
@@ -1493,6 +1504,8 @@ fn pretty_printing_compatibility_hack(item: &Item, sess: &Session) -> bool {
                             };
 
                             if crate_matches {
+                                // FIXME: make this translatable
+                                #[allow(rustc::untranslatable_diagnostic)]
                                 sess.psess.buffer_lint_with_diagnostic(
                                         PROC_MACRO_BACK_COMPAT,
                                         item.ident.span,
diff --git a/compiler/rustc_expand/src/config.rs b/compiler/rustc_expand/src/config.rs
index 921fea143124a..c95d7cdeb73ab 100644
--- a/compiler/rustc_expand/src/config.rs
+++ b/compiler/rustc_expand/src/config.rs
@@ -239,6 +239,7 @@ impl<'a> StripUnconfigured<'a> {
     /// Gives a compiler warning when the `cfg_attr` contains no attributes and
     /// is in the original source file. Gives a compiler error if the syntax of
     /// the attribute is incorrect.
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     pub(crate) fn expand_cfg_attr(&self, attr: &Attribute, recursive: bool) -> Vec<Attribute> {
         let Some((cfg_predicate, expanded_attrs)) =
             rustc_parse::parse_cfg_attr(attr, &self.sess.psess)
@@ -273,6 +274,7 @@ impl<'a> StripUnconfigured<'a> {
         }
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn expand_cfg_attr_item(
         &self,
         attr: &Attribute,
@@ -371,6 +373,7 @@ impl<'a> StripUnconfigured<'a> {
     }
 
     /// If attributes are not allowed on expressions, emit an error for `attr`
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     #[instrument(level = "trace", skip(self))]
     pub(crate) fn maybe_emit_expr_attr_err(&self, attr: &Attribute) {
         if self.features.is_some_and(|features| !features.stmt_expr_attributes)
@@ -384,7 +387,6 @@ impl<'a> StripUnconfigured<'a> {
             );
 
             if attr.is_doc_comment() {
-                #[allow(rustc::untranslatable_diagnostic)]
                 err.help("`///` is for documentation comments. For a plain comment, use `//`.");
             }
 
diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index 169973200aafa..fcc439e71f95b 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -783,6 +783,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         })
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn gate_proc_macro_attr_item(&self, span: Span, item: &Annotatable) {
         let kind = match item {
             Annotatable::Item(_)
@@ -825,6 +826,7 @@ impl<'a, 'b> MacroExpander<'a, 'b> {
         }
 
         impl<'ast, 'a> Visitor<'ast> for GateProcMacroInput<'a> {
+            #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
             fn visit_item(&mut self, item: &'ast ast::Item) {
                 match &item.kind {
                     ItemKind::Mod(_, mod_kind)
@@ -1689,6 +1691,7 @@ impl<'a, 'b> InvocationCollector<'a, 'b> {
 
     // Detect use of feature-gated or invalid attributes on macro invocations
     // since they will not be detected after macro expansion.
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_attributes(&self, attrs: &[ast::Attribute], call: &ast::MacCall) {
         let features = self.cx.ecfg.features;
         let mut attrs = attrs.iter().peekable();
diff --git a/compiler/rustc_expand/src/lib.rs b/compiler/rustc_expand/src/lib.rs
index 0e73abc9ed854..e550f7242c338 100644
--- a/compiler/rustc_expand/src/lib.rs
+++ b/compiler/rustc_expand/src/lib.rs
@@ -5,6 +5,7 @@
 #![feature(associated_type_defaults)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]
+#![feature(lint_reasons)]
 #![feature(macro_metavar_expr)]
 #![feature(map_try_insert)]
 #![feature(proc_macro_diagnostic)]
diff --git a/compiler/rustc_expand/src/proc_macro_server.rs b/compiler/rustc_expand/src/proc_macro_server.rs
index 32a083a72f013..ddc685c9d07da 100644
--- a/compiler/rustc_expand/src/proc_macro_server.rs
+++ b/compiler/rustc_expand/src/proc_macro_server.rs
@@ -517,6 +517,9 @@ impl server::FreeFunctions for Rustc<'_, '_> {
             Diag::new(&self.psess().dcx, diagnostic.level.to_internal(), message);
         diag.span(MultiSpan::from_spans(diagnostic.spans));
         for child in diagnostic.children {
+            // This message comes from another diagnostic, and we are just reconstructing the
+            // diagnostic, so there's no need for translation.
+            #[allow(rustc::untranslatable_diagnostic)]
             diag.sub(child.level.to_internal(), child.message, MultiSpan::from_spans(child.spans));
         }
         diag.emit();
diff --git a/compiler/rustc_expand/src/tests.rs b/compiler/rustc_expand/src/tests.rs
index 8c47b7594535c..a3510dc9bff4d 100644
--- a/compiler/rustc_expand/src/tests.rs
+++ b/compiler/rustc_expand/src/tests.rs
@@ -178,6 +178,7 @@ impl<T: Write> Write for Shared<T> {
     }
 }
 
+#[allow(rustc::untranslatable_diagnostic)] // no translation needed for tests
 fn test_harness(file_text: &str, span_labels: Vec<SpanLabel>, expected_output: &str) {
     create_default_session_globals_then(|| {
         let (handler, source_map, output) = create_test_handler();
@@ -192,7 +193,6 @@ fn test_harness(file_text: &str, span_labels: Vec<SpanLabel>, expected_output: &
             println!("text: {:?}", source_map.span_to_snippet(span));
         }
 
-        #[allow(rustc::untranslatable_diagnostic)]
         handler.span_err(msp, "foo");
 
         assert!(
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 3f971aad04242..0d51e1e46e06a 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -695,8 +695,8 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // Used by the `rustc::potential_query_instability` lint to warn methods which
     // might not be stable during incremental compilation.
     rustc_attr!(rustc_lint_query_instability, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE),
-    // Used by the `rustc::untranslatable_diagnostic` and `rustc::diagnostic_outside_of_impl` lints
-    // to assist in changes to diagnostic APIs.
+    // Used by the `rustc::diagnostic_outside_of_impl` lints to assist in changes to diagnostic
+    // APIs. Any function with this attribute will be checked by that lint.
     rustc_attr!(rustc_lint_diagnostics, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE),
     // Used by the `rustc::bad_opt_access` lint to identify `DebuggingOptions` and `CodegenOptions`
     // types (as well as any others in future).
diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index b2ec8e5342924..284d965979ece 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -320,6 +320,7 @@ pub struct Config {
 
 // JUSTIFICATION: before session exists, only config
 #[allow(rustc::bad_opt_access)]
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Send) -> R {
     trace!("run_compiler");
 
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 5e1fc248b801c..4f15d1c1d3a0b 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -590,7 +590,7 @@ fn test_codegen_options_tracking_hash() {
     tracked!(force_frame_pointers, Some(false));
     tracked!(force_unwind_tables, Some(true));
     tracked!(inline_threshold, Some(0xf007ba11));
-    tracked!(instrument_coverage, InstrumentCoverage::All);
+    tracked!(instrument_coverage, InstrumentCoverage::Yes);
     tracked!(link_dead_code, Some(true));
     tracked!(linker_plugin_lto, LinkerPluginLto::LinkerPluginAuto);
     tracked!(llvm_args, vec![String::from("1"), String::from("2")]);
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index bf3beb677aa6d..0d50200133cb2 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -160,6 +160,7 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce() -> R + Send, R: Send>(
     })
 }
 
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 fn load_backend_from_dylib(early_dcx: &EarlyDiagCtxt, path: &Path) -> MakeBackendFn {
     match unsafe { load_symbol_from_dylib::<MakeBackendFn>(path, "__rustc_codegen_backend") } {
         Ok(backend_sym) => backend_sym,
@@ -227,6 +228,7 @@ fn get_rustc_path_inner(bin_path: &str) -> Option<PathBuf> {
     })
 }
 
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 fn get_codegen_sysroot(
     early_dcx: &EarlyDiagCtxt,
     maybe_sysroot: &Option<PathBuf>,
@@ -319,6 +321,7 @@ fn get_codegen_sysroot(
     }
 }
 
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub(crate) fn check_attr_crate_type(
     sess: &Session,
     attrs: &[ast::Attribute],
diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
index f043a312c719c..89cdde11726ab 100644
--- a/compiler/rustc_lint/src/context.rs
+++ b/compiler/rustc_lint/src/context.rs
@@ -621,12 +621,13 @@ pub trait LintContext {
     /// Note that this function should only be called for [`LintExpectationId`]s
     /// retrieved from the current lint pass. Buffered or manually created ids can
     /// cause ICEs.
-    #[rustc_lint_diagnostics]
     fn fulfill_expectation(&self, expectation: LintExpectationId) {
         // We need to make sure that submitted expectation ids are correctly fulfilled suppressed
         // and stored between compilation sessions. To not manually do these steps, we simply create
-        // a dummy diagnostic and emit is as usual, which will be suppressed and stored like a normal
-        // expected lint diagnostic.
+        // a dummy diagnostic and emit it as usual, which will be suppressed and stored like a
+        // normal expected lint diagnostic.
+        #[allow(rustc::diagnostic_outside_of_impl)]
+        #[allow(rustc::untranslatable_diagnostic)]
         self.sess()
             .dcx()
             .struct_expect(
diff --git a/compiler/rustc_lint/src/internal.rs b/compiler/rustc_lint/src/internal.rs
index fdcd0192e6a74..3a8c8e79b4f28 100644
--- a/compiler/rustc_lint/src/internal.rs
+++ b/compiler/rustc_lint/src/internal.rs
@@ -10,7 +10,7 @@ use rustc_ast as ast;
 use rustc_hir::def::Res;
 use rustc_hir::{def_id::DefId, Expr, ExprKind, GenericArg, PatKind, Path, PathSegment, QPath};
 use rustc_hir::{BinOp, BinOpKind, HirId, Impl, Item, ItemKind, Node, Pat, Ty, TyKind};
-use rustc_middle::ty;
+use rustc_middle::ty::{self, Ty as MiddleTy};
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 use rustc_span::hygiene::{ExpnKind, MacroKind};
 use rustc_span::symbol::{kw, sym, Symbol};
@@ -338,10 +338,11 @@ impl<'tcx> LateLintPass<'tcx> for ExistingDocKeyword {
 }
 
 declare_tool_lint! {
-    /// The `untranslatable_diagnostic` lint detects diagnostics created
-    /// without using translatable Fluent strings.
+    /// The `untranslatable_diagnostic` lint detects messages passed to functions with `impl
+    /// Into<{D,Subd}iagMessage` parameters without using translatable Fluent strings.
     ///
-    /// More details on translatable diagnostics can be found [here](https://rustc-dev-guide.rust-lang.org/diagnostics/translation.html).
+    /// More details on translatable diagnostics can be found
+    /// [here](https://rustc-dev-guide.rust-lang.org/diagnostics/translation.html).
     pub rustc::UNTRANSLATABLE_DIAGNOSTIC,
     Deny,
     "prevent creation of diagnostics which cannot be translated",
@@ -349,11 +350,13 @@ declare_tool_lint! {
 }
 
 declare_tool_lint! {
-    /// The `diagnostic_outside_of_impl` lint detects diagnostics created manually,
-    /// and inside an `IntoDiagnostic`/`AddToDiagnostic` implementation,
-    /// or a `#[derive(Diagnostic)]`/`#[derive(Subdiagnostic)]` expansion.
+    /// The `diagnostic_outside_of_impl` lint detects calls to functions annotated with
+    /// `#[rustc_lint_diagnostics]` that are outside an `IntoDiagnostic`, `AddToDiagnostic`, or
+    /// `DecorateLint` impl, or a `#[derive(Diagnostic)]`, `#[derive(Subdiagnostic)]`,
+    /// `#[derive(DecorateLint)]` expansion.
     ///
-    /// More details on diagnostics implementations can be found [here](https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-structs.html).
+    /// More details on diagnostics implementations can be found
+    /// [here](https://rustc-dev-guide.rust-lang.org/diagnostics/diagnostic-structs.html).
     pub rustc::DIAGNOSTIC_OUTSIDE_OF_IMPL,
     Deny,
     "prevent creation of diagnostics outside of `IntoDiagnostic`/`AddToDiagnostic` impls",
@@ -364,54 +367,130 @@ declare_lint_pass!(Diagnostics => [UNTRANSLATABLE_DIAGNOSTIC, DIAGNOSTIC_OUTSIDE
 
 impl LateLintPass<'_> for Diagnostics {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
-        let Some((span, def_id, args)) = typeck_results_of_method_fn(cx, expr) else { return };
-        debug!(?span, ?def_id, ?args);
-        let has_attr = ty::Instance::resolve(cx.tcx, cx.param_env, def_id, args)
+        // Only check function calls and method calls.
+        let (span, def_id, fn_gen_args, call_tys) = match expr.kind {
+            ExprKind::Call(callee, args) => {
+                match cx.typeck_results().node_type(callee.hir_id).kind() {
+                    &ty::FnDef(def_id, fn_gen_args) => {
+                        let call_tys: Vec<_> =
+                            args.iter().map(|arg| cx.typeck_results().expr_ty(arg)).collect();
+                        (callee.span, def_id, fn_gen_args, call_tys)
+                    }
+                    _ => return, // occurs for fns passed as args
+                }
+            }
+            ExprKind::MethodCall(segment, _recv, args, _span) => {
+                let def_id = cx.typeck_results().type_dependent_def_id(expr.hir_id).unwrap();
+                let fn_gen_args = cx.typeck_results().node_args(expr.hir_id);
+                let mut call_tys: Vec<_> =
+                    args.iter().map(|arg| cx.typeck_results().expr_ty(arg)).collect();
+                call_tys.insert(0, cx.tcx.types.self_param); // dummy inserted for `self`
+                (segment.ident.span, def_id, fn_gen_args, call_tys)
+            }
+            _ => return,
+        };
+
+        // Is the callee marked with `#[rustc_lint_diagnostics]`?
+        let has_attr = ty::Instance::resolve(cx.tcx, cx.param_env, def_id, fn_gen_args)
             .ok()
             .flatten()
             .is_some_and(|inst| cx.tcx.has_attr(inst.def_id(), sym::rustc_lint_diagnostics));
-        if !has_attr {
-            return;
-        }
 
-        let mut found_parent_with_attr = false;
-        let mut found_impl = false;
-        for (hir_id, parent) in cx.tcx.hir().parent_iter(expr.hir_id) {
-            if let Some(owner_did) = hir_id.as_owner() {
-                found_parent_with_attr = found_parent_with_attr
-                    || cx.tcx.has_attr(owner_did, sym::rustc_lint_diagnostics);
+        // Closure: is the type `{D,Subd}iagMessage`?
+        let is_diag_message = |ty: MiddleTy<'_>| {
+            if let Some(adt_def) = ty.ty_adt_def()
+                && let Some(name) = cx.tcx.get_diagnostic_name(adt_def.did())
+                && matches!(name, sym::DiagMessage | sym::SubdiagMessage)
+            {
+                true
+            } else {
+                false
             }
+        };
 
-            debug!(?parent);
-            if let Node::Item(Item { kind: ItemKind::Impl(impl_), .. }) = parent
-                && let Impl { of_trait: Some(of_trait), .. } = impl_
-                && let Some(def_id) = of_trait.trait_def_id()
-                && let Some(name) = cx.tcx.get_diagnostic_name(def_id)
-                && matches!(name, sym::IntoDiagnostic | sym::AddToDiagnostic | sym::DecorateLint)
-            {
-                found_impl = true;
-                break;
+        // Does the callee have a `impl Into<{D,Subd}iagMessage>` parameter? (There should be at
+        // most one.)
+        let mut impl_into_diagnostic_message_param = None;
+        let fn_sig = cx.tcx.fn_sig(def_id).instantiate_identity().skip_binder();
+        let predicates = cx.tcx.predicates_of(def_id).instantiate_identity(cx.tcx).predicates;
+        for (i, &param_ty) in fn_sig.inputs().iter().enumerate() {
+            if let ty::Param(p) = param_ty.kind() {
+                // It is a type parameter. Check if it is `impl Into<{D,Subd}iagMessage>`.
+                for pred in predicates.iter() {
+                    if let Some(trait_pred) = pred.as_trait_clause()
+                        && let trait_ref = trait_pred.skip_binder().trait_ref
+                        && trait_ref.self_ty() == param_ty // correct predicate for the param?
+                        && cx.tcx.is_diagnostic_item(sym::Into, trait_ref.def_id)
+                        && let ty1 = trait_ref.args.type_at(1)
+                        && is_diag_message(ty1)
+                    {
+                        if impl_into_diagnostic_message_param.is_some() {
+                            cx.tcx.dcx().span_bug(
+                                span,
+                                "can't handle multiple `impl Into<{D,Sub}iagMessage>` params",
+                            );
+                        }
+                        impl_into_diagnostic_message_param = Some((i, p.name));
+                    }
+                }
             }
         }
-        debug!(?found_impl);
-        if !found_parent_with_attr && !found_impl {
-            cx.emit_span_lint(DIAGNOSTIC_OUTSIDE_OF_IMPL, span, DiagOutOfImpl);
+
+        // Is the callee interesting?
+        if !has_attr && impl_into_diagnostic_message_param.is_none() {
+            return;
         }
 
-        let mut found_diagnostic_message = false;
-        for ty in args.types() {
-            debug!(?ty);
-            if let Some(adt_def) = ty.ty_adt_def()
-                && let Some(name) = cx.tcx.get_diagnostic_name(adt_def.did())
-                && matches!(name, sym::DiagMessage | sym::SubdiagMessage)
+        // Is the parent method marked with `#[rustc_lint_diagnostics]`?
+        let mut parent_has_attr = false;
+        for (hir_id, _parent) in cx.tcx.hir().parent_iter(expr.hir_id) {
+            if let Some(owner_did) = hir_id.as_owner()
+                && cx.tcx.has_attr(owner_did, sym::rustc_lint_diagnostics)
             {
-                found_diagnostic_message = true;
+                parent_has_attr = true;
                 break;
             }
         }
-        debug!(?found_diagnostic_message);
-        if !found_parent_with_attr && !found_diagnostic_message {
-            cx.emit_span_lint(UNTRANSLATABLE_DIAGNOSTIC, span, UntranslatableDiag);
+
+        // Calls to `#[rustc_lint_diagnostics]`-marked functions should only occur:
+        // - inside an impl of `IntoDiagnostic`, `AddToDiagnostic`, or `DecorateLint`, or
+        // - inside a parent function that is itself marked with `#[rustc_lint_diagnostics]`.
+        //
+        // Otherwise, emit a `DIAGNOSTIC_OUTSIDE_OF_IMPL` lint.
+        if has_attr && !parent_has_attr {
+            let mut is_inside_appropriate_impl = false;
+            for (_hir_id, parent) in cx.tcx.hir().parent_iter(expr.hir_id) {
+                debug!(?parent);
+                if let Node::Item(Item { kind: ItemKind::Impl(impl_), .. }) = parent
+                    && let Impl { of_trait: Some(of_trait), .. } = impl_
+                    && let Some(def_id) = of_trait.trait_def_id()
+                    && let Some(name) = cx.tcx.get_diagnostic_name(def_id)
+                    && matches!(
+                        name,
+                        sym::IntoDiagnostic | sym::AddToDiagnostic | sym::DecorateLint
+                    )
+                {
+                    is_inside_appropriate_impl = true;
+                    break;
+                }
+            }
+            debug!(?is_inside_appropriate_impl);
+            if !is_inside_appropriate_impl {
+                cx.emit_span_lint(DIAGNOSTIC_OUTSIDE_OF_IMPL, span, DiagOutOfImpl);
+            }
+        }
+
+        // Calls to methods with an `impl Into<{D,Subd}iagMessage>` parameter must be passed an arg
+        // with type `{D,Subd}iagMessage` or `impl Into<{D,Subd}iagMessage>`. Otherwise, emit an
+        // `UNTRANSLATABLE_DIAGNOSTIC` lint.
+        if let Some((param_i, param_i_p_name)) = impl_into_diagnostic_message_param {
+            // Is the arg type `{Sub,D}iagMessage`or `impl Into<{Sub,D}iagMessage>`?
+            let arg_ty = call_tys[param_i];
+            let is_translatable = is_diag_message(arg_ty)
+                || matches!(arg_ty.kind(), ty::Param(p) if p.name == param_i_p_name);
+            if !is_translatable {
+                cx.emit_span_lint(UNTRANSLATABLE_DIAGNOSTIC, span, UntranslatableDiag);
+            }
         }
     }
 }
@@ -425,7 +504,7 @@ declare_tool_lint! {
     report_in_external_macro: true
 }
 
-declare_lint_pass!(BadOptAccess => [ BAD_OPT_ACCESS ]);
+declare_lint_pass!(BadOptAccess => [BAD_OPT_ACCESS]);
 
 impl LateLintPass<'_> for BadOptAccess {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
diff --git a/compiler/rustc_lint/src/let_underscore.rs b/compiler/rustc_lint/src/let_underscore.rs
index c552b9832553a..de642f373b5c4 100644
--- a/compiler/rustc_lint/src/let_underscore.rs
+++ b/compiler/rustc_lint/src/let_underscore.rs
@@ -104,6 +104,7 @@ const SYNC_GUARD_SYMBOLS: [Symbol; 3] = [
 ];
 
 impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_local(&mut self, cx: &LateContext<'_>, local: &hir::Local<'_>) {
         if matches!(local.source, rustc_hir::LocalSource::AsyncFn) {
             return;
diff --git a/compiler/rustc_lint/src/levels.rs b/compiler/rustc_lint/src/levels.rs
index 906cd1d1283f8..2f08cd53b75a1 100644
--- a/compiler/rustc_lint/src/levels.rs
+++ b/compiler/rustc_lint/src/levels.rs
@@ -724,6 +724,7 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         };
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn add(&mut self, attrs: &[ast::Attribute], is_crate_node: bool, source_hir_id: Option<HirId>) {
         let sess = self.sess;
         for (attr_index, attr) in attrs.iter().enumerate() {
diff --git a/compiler/rustc_metadata/src/creader.rs b/compiler/rustc_metadata/src/creader.rs
index 0d37c0feb0c24..72757d90e4238 100644
--- a/compiler/rustc_metadata/src/creader.rs
+++ b/compiler/rustc_metadata/src/creader.rs
@@ -947,6 +947,7 @@ impl<'a, 'tcx> CrateLoader<'a, 'tcx> {
         }
     }
 
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn report_unused_deps(&mut self, krate: &ast::Crate) {
         // Make a point span rather than covering the whole file
         let span = krate.spans.inner_span.shrink_to_lo();
diff --git a/compiler/rustc_metadata/src/native_libs.rs b/compiler/rustc_metadata/src/native_libs.rs
index cdcc586b09e70..baa2e1ff60215 100644
--- a/compiler/rustc_metadata/src/native_libs.rs
+++ b/compiler/rustc_metadata/src/native_libs.rs
@@ -93,6 +93,7 @@ struct Collector<'tcx> {
 }
 
 impl<'tcx> Collector<'tcx> {
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn process_module(&mut self, module: &ForeignModule) {
         let ForeignModule { def_id, abi, ref foreign_items } = *module;
         let def_id = def_id.expect_local();
diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index dda41f70f067a..b1bfd2f1105a8 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -17,6 +17,7 @@ use rustc_target::abi::call::FnAbi;
 use rustc_target::abi::*;
 use rustc_target::spec::{abi::Abi as SpecAbi, HasTargetSpec, PanicStrategy, Target};
 
+use std::borrow::Cow;
 use std::cmp;
 use std::fmt;
 use std::num::NonZero;
@@ -268,7 +269,7 @@ pub struct LayoutCx<'tcx, C> {
 impl<'tcx> LayoutCalculator for LayoutCx<'tcx, TyCtxt<'tcx>> {
     type TargetDataLayoutRef = &'tcx TargetDataLayout;
 
-    fn delayed_bug(&self, txt: String) {
+    fn delayed_bug(&self, txt: impl Into<Cow<'static, str>>) {
         self.tcx.dcx().delayed_bug(txt);
     }
 
diff --git a/compiler/rustc_middle/src/ty/sty.rs b/compiler/rustc_middle/src/ty/sty.rs
index a0baaa3ce2832..427c0f04bd11e 100644
--- a/compiler/rustc_middle/src/ty/sty.rs
+++ b/compiler/rustc_middle/src/ty/sty.rs
@@ -13,7 +13,7 @@ use crate::ty::{GenericArg, GenericArgs, GenericArgsRef};
 use crate::ty::{List, ParamEnv};
 use hir::def::DefKind;
 use rustc_data_structures::captures::Captures;
-use rustc_errors::{DiagArgValue, DiagMessage, ErrorGuaranteed, IntoDiagnosticArg, MultiSpan};
+use rustc_errors::{DiagArgValue, ErrorGuaranteed, IntoDiagnosticArg, MultiSpan};
 use rustc_hir as hir;
 use rustc_hir::def_id::DefId;
 use rustc_hir::LangItem;
@@ -1543,7 +1543,7 @@ impl<'tcx> Ty<'tcx> {
     pub fn new_error_with_message<S: Into<MultiSpan>>(
         tcx: TyCtxt<'tcx>,
         span: S,
-        msg: impl Into<DiagMessage>,
+        msg: impl Into<Cow<'static, str>>,
     ) -> Ty<'tcx> {
         let reported = tcx.dcx().span_delayed_bug(span, msg);
         Ty::new(tcx, Error(reported))
diff --git a/compiler/rustc_passes/src/check_attr.rs b/compiler/rustc_passes/src/check_attr.rs
index 04c0cf7436e2b..a99db9cb8cc58 100644
--- a/compiler/rustc_passes/src/check_attr.rs
+++ b/compiler/rustc_passes/src/check_attr.rs
@@ -1074,6 +1074,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     /// of one item. Read the documentation of [`check_doc_inline`] for more information.
     ///
     /// [`check_doc_inline`]: Self::check_doc_inline
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_doc_attrs(
         &self,
         attr: &Attribute,
@@ -1756,6 +1757,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     }
 
     /// Checks if the `#[repr]` attributes on `item` are valid.
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn check_repr(
         &self,
         attrs: &[Attribute],
@@ -2328,6 +2330,7 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
 
             let hir_sig = tcx.hir().fn_sig_by_hir_id(hir_id);
             if let Some(hir_sig) = hir_sig {
+                #[allow(rustc::diagnostic_outside_of_impl)] // FIXME
                 match terr {
                     TypeError::ArgumentMutability(idx) | TypeError::ArgumentSorts(_, idx) => {
                         if let Some(ty) = hir_sig.decl.inputs.get(idx) {
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index 02792491f5ed0..30a65d69c4ef8 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -77,6 +77,7 @@ impl<'tcx> CheckConstVisitor<'tcx> {
     }
 
     /// Emits an error when an unsupported expression is found in a const context.
+    #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
     fn const_check_violated(&self, expr: NonConstExpr, span: Span) {
         let Self { tcx, def_id, const_kind } = *self;
 
diff --git a/compiler/rustc_passes/src/entry.rs b/compiler/rustc_passes/src/entry.rs
index 97c70e327f0fe..5246389248e9f 100644
--- a/compiler/rustc_passes/src/entry.rs
+++ b/compiler/rustc_passes/src/entry.rs
@@ -114,6 +114,7 @@ fn find_item(id: ItemId, ctxt: &mut EntryContext<'_>) {
     }
 }
 
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 fn configure_main(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) -> Option<(DefId, EntryFnType)> {
     if let Some((def_id, _)) = visitor.start_fn {
         Some((def_id.to_def_id(), EntryFnType::Start))
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs
index 833ebfa03e5fc..0bb2a69ae9926 100644
--- a/compiler/rustc_resolve/src/diagnostics.rs
+++ b/compiler/rustc_resolve/src/diagnostics.rs
@@ -1736,7 +1736,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
     }
 
     fn report_privacy_error(&mut self, privacy_error: &PrivacyError<'a>) {
-        let PrivacyError { ident, binding, outermost_res, parent_scope, dedup_span } =
+        let PrivacyError { ident, binding, outermost_res, parent_scope, single_nested, dedup_span } =
             *privacy_error;
 
         let res = binding.res();
@@ -1775,7 +1775,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 &import_suggestions,
                 Instead::Yes,
                 FoundUse::Yes,
-                DiagMode::Import,
+                DiagMode::Import { append: single_nested },
                 vec![],
                 "",
             );
@@ -2701,7 +2701,11 @@ pub(crate) enum DiagMode {
     /// The binding is part of a pattern
     Pattern,
     /// The binding is part of a use statement
-    Import,
+    Import {
+        /// `true` mean add the tips afterward for case `use a::{b,c}`,
+        /// rather than replacing within.
+        append: bool,
+    },
 }
 
 pub(crate) fn import_candidates(
@@ -2726,6 +2730,8 @@ pub(crate) fn import_candidates(
     );
 }
 
+type PathString<'a> = (String, &'a str, Option<DefId>, &'a Option<String>, bool);
+
 /// When an entity with a given name is not available in scope, we search for
 /// entities with that name in all crates. This method allows outputting the
 /// results of this search in a programmer-friendly way. If any entities are
@@ -2746,10 +2752,8 @@ fn show_candidates(
         return false;
     }
 
-    let mut accessible_path_strings: Vec<(String, &str, Option<DefId>, &Option<String>, bool)> =
-        Vec::new();
-    let mut inaccessible_path_strings: Vec<(String, &str, Option<DefId>, &Option<String>, bool)> =
-        Vec::new();
+    let mut accessible_path_strings: Vec<PathString<'_>> = Vec::new();
+    let mut inaccessible_path_strings: Vec<PathString<'_>> = Vec::new();
 
     candidates.iter().for_each(|c| {
         if c.accessible {
@@ -2811,6 +2815,15 @@ fn show_candidates(
             err.note(note.clone());
         }
 
+        let append_candidates = |msg: &mut String, accessible_path_strings: Vec<PathString<'_>>| {
+            msg.push(':');
+
+            for candidate in accessible_path_strings {
+                msg.push('\n');
+                msg.push_str(&candidate.0);
+            }
+        };
+
         if let Some(span) = use_placement_span {
             let (add_use, trailing) = match mode {
                 DiagMode::Pattern => {
@@ -2822,7 +2835,7 @@ fn show_candidates(
                     );
                     return true;
                 }
-                DiagMode::Import => ("", ""),
+                DiagMode::Import { .. } => ("", ""),
                 DiagMode::Normal => ("use ", ";\n"),
             };
             for candidate in &mut accessible_path_strings {
@@ -2839,13 +2852,22 @@ fn show_candidates(
                     format!("{add_use}{}{append}{trailing}{additional_newline}", &candidate.0);
             }
 
-            err.span_suggestions_with_style(
-                span,
-                msg,
-                accessible_path_strings.into_iter().map(|a| a.0),
-                Applicability::MaybeIncorrect,
-                SuggestionStyle::ShowAlways,
-            );
+            match mode {
+                DiagMode::Import { append: true, .. } => {
+                    append_candidates(&mut msg, accessible_path_strings);
+                    err.span_help(span, msg);
+                }
+                _ => {
+                    err.span_suggestions_with_style(
+                        span,
+                        msg,
+                        accessible_path_strings.into_iter().map(|a| a.0),
+                        Applicability::MaybeIncorrect,
+                        SuggestionStyle::ShowAlways,
+                    );
+                }
+            }
+
             if let [first, .., last] = &path[..] {
                 let sp = first.ident.span.until(last.ident.span);
                 // Our suggestion is empty, so make sure the span is not empty (or we'd ICE).
@@ -2860,17 +2882,11 @@ fn show_candidates(
                 }
             }
         } else {
-            msg.push(':');
-
-            for candidate in accessible_path_strings {
-                msg.push('\n');
-                msg.push_str(&candidate.0);
-            }
-
+            append_candidates(&mut msg, accessible_path_strings);
             err.help(msg);
         }
         true
-    } else if !(inaccessible_path_strings.is_empty() || matches!(mode, DiagMode::Import)) {
+    } else if !(inaccessible_path_strings.is_empty() || matches!(mode, DiagMode::Import { .. })) {
         let prefix =
             if let DiagMode::Pattern = mode { "you might have meant to match on " } else { "" };
         if let [(name, descr, def_id, note, _)] = &inaccessible_path_strings[..] {
diff --git a/compiler/rustc_resolve/src/ident.rs b/compiler/rustc_resolve/src/ident.rs
index a9fdddbfab90f..6518d9735ae52 100644
--- a/compiler/rustc_resolve/src/ident.rs
+++ b/compiler/rustc_resolve/src/ident.rs
@@ -868,7 +868,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             .into_iter()
             .find_map(|binding| if binding == ignore_binding { None } else { binding });
 
-        if let Some(Finalize { path_span, report_private, used, .. }) = finalize {
+        if let Some(Finalize { path_span, report_private, used, root_span, .. }) = finalize {
             let Some(binding) = binding else {
                 return Err((Determined, Weak::No));
             };
@@ -881,6 +881,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         dedup_span: path_span,
                         outermost_res: None,
                         parent_scope: *parent_scope,
+                        single_nested: path_span != root_span,
                     });
                 } else {
                     return Err((Determined, Weak::No));
diff --git a/compiler/rustc_resolve/src/imports.rs b/compiler/rustc_resolve/src/imports.rs
index 6647a9a279285..9e5b2fe094f4c 100644
--- a/compiler/rustc_resolve/src/imports.rs
+++ b/compiler/rustc_resolve/src/imports.rs
@@ -715,7 +715,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                         &mut diag,
                         Some(err.span),
                         candidates,
-                        DiagMode::Import,
+                        DiagMode::Import { append: false },
                         (source != target)
                             .then(|| format!(" as {target}"))
                             .as_deref()
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
index 2c80fbdab36d7..83ee1d8bdcb10 100644
--- a/compiler/rustc_resolve/src/late.rs
+++ b/compiler/rustc_resolve/src/late.rs
@@ -3953,6 +3953,7 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             // Avoid recording definition of `A::B` in `<T as A>::B::C`.
             self.r.record_partial_res(node_id, partial_res);
             self.resolve_elided_lifetimes_in_path(partial_res, path, source, path_span);
+            self.lint_unused_qualifications(path, ns, finalize);
         }
 
         partial_res
@@ -4145,39 +4146,6 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             PathResult::Indeterminate => bug!("indeterminate path result in resolve_qpath"),
         };
 
-        if path.iter().all(|seg| !seg.ident.span.from_expansion()) {
-            let end_pos =
-                path.iter().position(|seg| seg.has_generic_args).map_or(path.len(), |pos| pos + 1);
-            let unqualified =
-                path[..end_pos].iter().enumerate().skip(1).rev().find_map(|(i, seg)| {
-                    // Preserve the current namespace for the final path segment, but use the type
-                    // namespace for all preceding segments
-                    //
-                    // e.g. for `std::env::args` check the `ValueNS` for `args` but the `TypeNS` for
-                    // `std` and `env`
-                    //
-                    // If the final path segment is beyond `end_pos` all the segments to check will
-                    // use the type namespace
-                    let ns = if i + 1 == path.len() { ns } else { TypeNS };
-                    let res = self.r.partial_res_map.get(&seg.id?)?.full_res()?;
-                    let binding = self.resolve_ident_in_lexical_scope(seg.ident, ns, None, None)?;
-
-                    (res == binding.res()).then_some(seg)
-                });
-
-            if let Some(unqualified) = unqualified {
-                self.r.lint_buffer.buffer_lint_with_diagnostic(
-                    lint::builtin::UNUSED_QUALIFICATIONS,
-                    finalize.node_id,
-                    finalize.path_span,
-                    "unnecessary qualification",
-                    lint::BuiltinLintDiag::UnusedQualifications {
-                        removal_span: finalize.path_span.until(unqualified.ident.span),
-                    },
-                );
-            }
-        }
-
         Ok(Some(result))
     }
 
@@ -4656,6 +4624,42 @@ impl<'a: 'ast, 'b, 'ast, 'tcx> LateResolutionVisitor<'a, 'b, 'ast, 'tcx> {
             self.r.doc_link_traits_in_scope = doc_link_traits_in_scope;
         }
     }
+
+    fn lint_unused_qualifications(&mut self, path: &[Segment], ns: Namespace, finalize: Finalize) {
+        if path.iter().any(|seg| seg.ident.span.from_expansion()) {
+            return;
+        }
+
+        let end_pos =
+            path.iter().position(|seg| seg.has_generic_args).map_or(path.len(), |pos| pos + 1);
+        let unqualified = path[..end_pos].iter().enumerate().skip(1).rev().find_map(|(i, seg)| {
+            // Preserve the current namespace for the final path segment, but use the type
+            // namespace for all preceding segments
+            //
+            // e.g. for `std::env::args` check the `ValueNS` for `args` but the `TypeNS` for
+            // `std` and `env`
+            //
+            // If the final path segment is beyond `end_pos` all the segments to check will
+            // use the type namespace
+            let ns = if i + 1 == path.len() { ns } else { TypeNS };
+            let res = self.r.partial_res_map.get(&seg.id?)?.full_res()?;
+            let binding = self.resolve_ident_in_lexical_scope(seg.ident, ns, None, None)?;
+
+            (res == binding.res()).then_some(seg)
+        });
+
+        if let Some(unqualified) = unqualified {
+            self.r.lint_buffer.buffer_lint_with_diagnostic(
+                lint::builtin::UNUSED_QUALIFICATIONS,
+                finalize.node_id,
+                finalize.path_span,
+                "unnecessary qualification",
+                lint::BuiltinLintDiag::UnusedQualifications {
+                    removal_span: path[0].ident.span.until(unqualified.ident.span),
+                },
+            );
+        }
+    }
 }
 
 /// Walks the whole crate in DFS order, visiting each item, counting the declared number of
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 0434ff171934e..5de147c2b2444 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -729,6 +729,8 @@ struct PrivacyError<'a> {
     dedup_span: Span,
     outermost_res: Option<(Res, Ident)>,
     parent_scope: ParentScope<'a>,
+    /// Is the format `use a::{b,c}`?
+    single_nested: bool,
 }
 
 #[derive(Debug)]
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index dadbcff6f68cd..61a220428b03b 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -1,6 +1,8 @@
 //! Contains infrastructure for configuring the compiler, including parsing
 //! command-line options.
 
+#![allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
+
 pub use crate::options::*;
 
 use crate::errors::FileWriteFail;
@@ -146,8 +148,10 @@ pub enum LtoCli {
 /// unless the function has type parameters.
 #[derive(Clone, Copy, PartialEq, Hash, Debug)]
 pub enum InstrumentCoverage {
-    /// Default `-C instrument-coverage` or `-C instrument-coverage=statement`
-    All,
+    /// `-C instrument-coverage=no` (or `off`, `false` etc.)
+    No,
+    /// `-C instrument-coverage` or `-C instrument-coverage=yes`
+    Yes,
     /// Additionally, instrument branches and output branch coverage.
     /// `-Zunstable-options -C instrument-coverage=branch`
     Branch,
@@ -155,8 +159,6 @@ pub enum InstrumentCoverage {
     ExceptUnusedGenerics,
     /// `-Zunstable-options -C instrument-coverage=except-unused-functions`
     ExceptUnusedFunctions,
-    /// `-C instrument-coverage=off` (or `no`, etc.)
-    Off,
 }
 
 /// Settings for `-Z instrument-xray` flag.
@@ -2468,9 +2470,7 @@ pub fn parse_externs(
             ));
             let adjusted_name = name.replace('-', "_");
             if is_ascii_ident(&adjusted_name) {
-                // FIXME: make this translatable
-                #[allow(rustc::diagnostic_outside_of_impl)]
-                #[allow(rustc::untranslatable_diagnostic)]
+                #[allow(rustc::diagnostic_outside_of_impl)] // FIXME
                 error.help(format!(
                     "consider replacing the dashes with underscores: `{adjusted_name}`"
                 ));
@@ -2722,7 +2722,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
     // This is what prevents them from being used on stable compilers.
     match cg.instrument_coverage {
         // Stable values:
-        InstrumentCoverage::All | InstrumentCoverage::Off => {}
+        InstrumentCoverage::Yes | InstrumentCoverage::No => {}
         // Unstable values:
         InstrumentCoverage::Branch
         | InstrumentCoverage::ExceptUnusedFunctions
@@ -2736,7 +2736,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         }
     }
 
-    if cg.instrument_coverage != InstrumentCoverage::Off {
+    if cg.instrument_coverage != InstrumentCoverage::No {
         if cg.profile_generate.enabled() || cg.profile_use.is_some() {
             early_dcx.early_fatal(
                 "option `-C instrument-coverage` is not compatible with either `-C profile-use` \
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 55e1556cdf8d6..93bef82e4ba15 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -320,6 +320,7 @@ macro_rules! redirect_field {
 type OptionSetter<O> = fn(&mut O, v: Option<&str>) -> bool;
 type OptionDescrs<O> = &'static [(&'static str, OptionSetter<O>, &'static str, &'static str)];
 
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 fn build_options<O: Default>(
     early_dcx: &EarlyDiagCtxt,
     matches: &getopts::Matches,
@@ -394,8 +395,7 @@ mod desc {
     pub const parse_linker_flavor: &str = ::rustc_target::spec::LinkerFlavorCli::one_of();
     pub const parse_optimization_fuel: &str = "crate=integer";
     pub const parse_dump_mono_stats: &str = "`markdown` (default) or `json`";
-    pub const parse_instrument_coverage: &str =
-        "`all` (default), `branch`, `except-unused-generics`, `except-unused-functions`, or `off`";
+    pub const parse_instrument_coverage: &str = "either a boolean (`yes`, `no`, `on`, `off`, etc) or (unstable) one of `branch`, `except-unused-generics`, `except-unused-functions`";
     pub const parse_instrument_xray: &str = "either a boolean (`yes`, `no`, `on`, `off`, etc), or a comma separated list of settings: `always` or `never` (mutually exclusive), `ignore-loops`, `instruction-threshold=N`, `skip-entry`, `skip-exit`";
     pub const parse_unpretty: &str = "`string` or `string=string`";
     pub const parse_treat_err_as_bug: &str = "either no value or a non-negative number";
@@ -918,18 +918,18 @@ mod parse {
         if v.is_some() {
             let mut bool_arg = false;
             if parse_bool(&mut bool_arg, v) {
-                *slot = if bool_arg { InstrumentCoverage::All } else { InstrumentCoverage::Off };
+                *slot = if bool_arg { InstrumentCoverage::Yes } else { InstrumentCoverage::No };
                 return true;
             }
         }
 
         let Some(v) = v else {
-            *slot = InstrumentCoverage::All;
+            *slot = InstrumentCoverage::Yes;
             return true;
         };
 
         *slot = match v {
-            "all" => InstrumentCoverage::All,
+            "all" => InstrumentCoverage::Yes,
             "branch" => InstrumentCoverage::Branch,
             "except-unused-generics" | "except_unused_generics" => {
                 InstrumentCoverage::ExceptUnusedGenerics
@@ -937,7 +937,7 @@ mod parse {
             "except-unused-functions" | "except_unused_functions" => {
                 InstrumentCoverage::ExceptUnusedFunctions
             }
-            "off" | "no" | "n" | "false" | "0" => InstrumentCoverage::Off,
+            "0" => InstrumentCoverage::No,
             _ => return false,
         };
         true
@@ -1444,15 +1444,15 @@ options! {
     inline_threshold: Option<u32> = (None, parse_opt_number, [TRACKED],
         "set the threshold for inlining a function"),
     #[rustc_lint_opt_deny_field_access("use `Session::instrument_coverage` instead of this field")]
-    instrument_coverage: InstrumentCoverage = (InstrumentCoverage::Off, parse_instrument_coverage, [TRACKED],
+    instrument_coverage: InstrumentCoverage = (InstrumentCoverage::No, parse_instrument_coverage, [TRACKED],
         "instrument the generated code to support LLVM source-based code coverage \
         reports (note, the compiler build config must include `profiler = true`); \
         implies `-C symbol-mangling-version=v0`. Optional values are:
-        `=all` (implicit value)
-        `=branch`
-        `=except-unused-generics`
-        `=except-unused-functions`
-        `=off` (default)"),
+        `=no` `=n` `=off` `=false` (default)
+        `=yes` `=y` `=on` `=true` (implicit value)
+        `=branch` (unstable)
+        `=except-unused-generics` (unstable)
+        `=except-unused-functions` (unstable)"),
     link_arg: (/* redirected to link_args */) = ((), parse_string_push, [UNTRACKED],
         "a single extra argument to append to the linker invocation (can be used several times)"),
     link_args: Vec<String> = (Vec::new(), parse_list, [UNTRACKED],
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index 506bd5d5dbd81..398138d7e1ff3 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -168,6 +168,7 @@ pub fn add_feature_diagnostics<G: EmissionGuarantee>(
 /// This variant allows you to control whether it is a library or language feature.
 /// Almost always, you want to use this for a language feature. If so, prefer
 /// `add_feature_diagnostics`.
+#[allow(rustc::diagnostic_outside_of_impl)] // FIXME
 pub fn add_feature_diagnostics_for_issue<G: EmissionGuarantee>(
     err: &mut Diag<'_, G>,
     sess: &Session,
diff --git a/compiler/rustc_session/src/search_paths.rs b/compiler/rustc_session/src/search_paths.rs
index 9b913c76998e0..32d5e430717bd 100644
--- a/compiler/rustc_session/src/search_paths.rs
+++ b/compiler/rustc_session/src/search_paths.rs
@@ -61,6 +61,7 @@ impl SearchPath {
             (PathKind::All, path)
         };
         if path.is_empty() {
+            #[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
             early_dcx.early_fatal("empty search path given via `-L`");
         }
 
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 4f4d8fabb7261..ae1dbd13204b0 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -312,6 +312,7 @@ impl Session {
     ) -> Diag<'a> {
         let mut err = self.dcx().create_err(err);
         if err.code.is_none() {
+            #[allow(rustc::diagnostic_outside_of_impl)]
             err.code(E0658);
         }
         add_feature_diagnostics(&mut err, self, feature);
@@ -352,7 +353,7 @@ impl Session {
     }
 
     pub fn instrument_coverage(&self) -> bool {
-        self.opts.cg.instrument_coverage() != InstrumentCoverage::Off
+        self.opts.cg.instrument_coverage() != InstrumentCoverage::No
     }
 
     pub fn instrument_coverage_branch(&self) -> bool {
@@ -898,19 +899,6 @@ impl Session {
     }
 
     pub fn should_prefer_remapped_for_codegen(&self) -> bool {
-        // bail out, if any of the requested crate types aren't:
-        // "compiled executables or libraries"
-        for crate_type in &self.opts.crate_types {
-            match crate_type {
-                CrateType::Executable
-                | CrateType::Dylib
-                | CrateType::Rlib
-                | CrateType::Staticlib
-                | CrateType::Cdylib => continue,
-                CrateType::ProcMacro => return false,
-            }
-        }
-
         let has_split_debuginfo = match self.split_debuginfo() {
             SplitDebuginfo::Off => false,
             SplitDebuginfo::Packed => true,
@@ -1022,6 +1010,7 @@ fn default_emitter(
 
 // JUSTIFICATION: literally session construction
 #[allow(rustc::bad_opt_access)]
+#[allow(rustc::untranslatable_diagnostic)] // FIXME: make this translatable
 pub fn build_session(
     early_dcx: EarlyDiagCtxt,
     sopts: config::Options,
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index 616a7ccc7c64f..0c974ef4ca3eb 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -427,6 +427,17 @@ impl FileName {
         src.hash(&mut hasher);
         FileName::InlineAsm(hasher.finish())
     }
+
+    /// Returns the path suitable for reading from the file system on the local host,
+    /// if this information exists.
+    /// Avoid embedding this in build artifacts; see `remapped_path_if_available()` for that.
+    pub fn into_local_path(self) -> Option<PathBuf> {
+        match self {
+            FileName::Real(path) => path.into_local_path(),
+            FileName::DocTest(path, _) => Some(path),
+            _ => None,
+        }
+    }
 }
 
 /// Represents a span.
diff --git a/library/test/src/formatters/terse.rs b/library/test/src/formatters/terse.rs
index 2931ca6ead0ac..22c28e4954eff 100644
--- a/library/test/src/formatters/terse.rs
+++ b/library/test/src/formatters/terse.rs
@@ -23,6 +23,7 @@ pub(crate) struct TerseFormatter<T> {
     max_name_len: usize,
 
     test_count: usize,
+    test_column: usize,
     total_test_count: usize,
 }
 
@@ -39,6 +40,7 @@ impl<T: Write> TerseFormatter<T> {
             max_name_len,
             is_multithreaded,
             test_count: 0,
+            test_column: 0,
             total_test_count: 0, // initialized later, when write_run_start is called
         }
     }
@@ -47,8 +49,20 @@ impl<T: Write> TerseFormatter<T> {
         self.write_short_result(".", term::color::GREEN)
     }
 
-    pub fn write_failed(&mut self) -> io::Result<()> {
-        self.write_short_result("F", term::color::RED)
+    pub fn write_failed(&mut self, name: &str) -> io::Result<()> {
+        // Put failed tests on their own line and include the test name, so that it's faster
+        // to see which test failed without having to wait for them all to run.
+
+        // normally, we write the progress unconditionally, even if the previous line was cut short.
+        // but if this is the very first column, no short results will have been printed and we'll end up with *only* the progress on the line.
+        // avoid this.
+        if self.test_column != 0 {
+            self.write_progress()?;
+        }
+        self.test_count += 1;
+        self.write_plain(format!("{name} --- "))?;
+        self.write_pretty("FAILED", term::color::RED)?;
+        self.write_plain("\n")
     }
 
     pub fn write_ignored(&mut self) -> io::Result<()> {
@@ -65,15 +79,22 @@ impl<T: Write> TerseFormatter<T> {
         color: term::color::Color,
     ) -> io::Result<()> {
         self.write_pretty(result, color)?;
-        if self.test_count % QUIET_MODE_MAX_COLUMN == QUIET_MODE_MAX_COLUMN - 1 {
+        self.test_count += 1;
+        self.test_column += 1;
+        if self.test_column % QUIET_MODE_MAX_COLUMN == QUIET_MODE_MAX_COLUMN - 1 {
             // We insert a new line regularly in order to flush the
             // screen when dealing with line-buffered output (e.g., piping to
             // `stamp` in the rust CI).
-            let out = format!(" {}/{}\n", self.test_count + 1, self.total_test_count);
-            self.write_plain(out)?;
+            self.write_progress()?;
         }
 
-        self.test_count += 1;
+        Ok(())
+    }
+
+    fn write_progress(&mut self) -> io::Result<()> {
+        let out = format!(" {}/{}\n", self.test_count, self.total_test_count);
+        self.write_plain(out)?;
+        self.test_column = 0;
         Ok(())
     }
 
@@ -213,7 +234,7 @@ impl<T: Write> OutputFormatter for TerseFormatter<T> {
         match *result {
             TestResult::TrOk => self.write_ok(),
             TestResult::TrFailed | TestResult::TrFailedMsg(_) | TestResult::TrTimedFail => {
-                self.write_failed()
+                self.write_failed(desc.name.as_slice())
             }
             TestResult::TrIgnored => self.write_ignored(),
             TestResult::TrBench(ref bs) => {
diff --git a/src/bootstrap/src/utils/render_tests.rs b/src/bootstrap/src/utils/render_tests.rs
index bfbb53f8c8121..cbd01606a895a 100644
--- a/src/bootstrap/src/utils/render_tests.rs
+++ b/src/bootstrap/src/utils/render_tests.rs
@@ -166,7 +166,7 @@ impl<'a> Renderer<'a> {
         println!();
     }
 
-    fn render_test_outcome_terse(&mut self, outcome: Outcome<'_>, _: &TestOutcome) {
+    fn render_test_outcome_terse(&mut self, outcome: Outcome<'_>, test: &TestOutcome) {
         if self.terse_tests_in_line != 0 && self.terse_tests_in_line % TERSE_TESTS_PER_LINE == 0 {
             if let Some(total) = self.tests_count {
                 let total = total.to_string();
@@ -178,7 +178,7 @@ impl<'a> Renderer<'a> {
         }
 
         self.terse_tests_in_line += 1;
-        self.builder.colored_stdout(|stdout| outcome.write_short(stdout)).unwrap();
+        self.builder.colored_stdout(|stdout| outcome.write_short(stdout, &test.name)).unwrap();
         let _ = std::io::stdout().flush();
     }
 
@@ -300,7 +300,7 @@ enum Outcome<'a> {
 }
 
 impl Outcome<'_> {
-    fn write_short(&self, writer: &mut dyn WriteColor) -> Result<(), std::io::Error> {
+    fn write_short(&self, writer: &mut dyn WriteColor, name: &str) -> Result<(), std::io::Error> {
         match self {
             Outcome::Ok => {
                 writer.set_color(ColorSpec::new().set_fg(Some(Color::Green)))?;
@@ -311,8 +311,11 @@ impl Outcome<'_> {
                 write!(writer, "b")?;
             }
             Outcome::Failed => {
+                // Put failed tests on their own line and include the test name, so that it's faster
+                // to see which test failed without having to wait for them all to run.
+                writeln!(writer)?;
                 writer.set_color(ColorSpec::new().set_fg(Some(Color::Red)))?;
-                write!(writer, "F")?;
+                writeln!(writer, "{name} ... F")?;
             }
             Outcome::Ignored { .. } => {
                 writer.set_color(ColorSpec::new().set_fg(Some(Color::Yellow)))?;
diff --git a/src/doc/rustc/src/instrument-coverage.md b/src/doc/rustc/src/instrument-coverage.md
index 5b76631833108..2f93252eddcd7 100644
--- a/src/doc/rustc/src/instrument-coverage.md
+++ b/src/doc/rustc/src/instrument-coverage.md
@@ -331,10 +331,29 @@ $ llvm-cov report \
 
 ## `-C instrument-coverage=<options>`
 
--   `-C instrument-coverage=all`: Instrument all functions, including unused functions and unused generics. (This is the same as `-C instrument-coverage`, with no value.)
--   `-C instrument-coverage=off`: Do not instrument any functions. (This is the same as simply not including the `-C instrument-coverage` option.)
--   `-Zunstable-options -C instrument-coverage=except-unused-generics`: Instrument all functions except unused generics.
--   `-Zunstable-options -C instrument-coverage=except-unused-functions`: Instrument only used (called) functions and instantiated generic functions.
+- `-C instrument-coverage=no` (or `n`/`off`/`false`):
+  Don't enable coverage instrumentation. No functions will be instrumented for coverage.
+  - This is the same as not using the `-C instrument-coverage` flag at all.
+- `-C instrument-coverage=yes` (or `y`/`on`/`true`):
+  Enable coverage instrumentation with the default behaviour.
+  Currently this instruments all functions, including unused functions and unused generics.
+  - This is the same as `-C instrument-coverage` with no value.
+
+### Other values
+
+- `-C instrument-coverage=all`:
+  Currently an alias for `yes`, but may behave differently in the future if
+  more fine-grained coverage options are added.
+  Using this value is currently not recommended.
+
+### Unstable values
+
+- `-Z unstable-options -C instrument-coverage=branch`:
+  Placeholder for potential branch coverage support in the future.
+- `-Z unstable-options -C instrument-coverage=except-unused-generics`:
+  Instrument all functions except unused generics.
+- `-Z unstable-options -C instrument-coverage=except-unused-functions`:
+  Instrument only used (called) functions and instantiated generic functions.
 
 ## Other references
 
diff --git a/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs b/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs
index be1c8d9094bfb..a1be60180838c 100644
--- a/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs
+++ b/src/tools/rust-analyzer/crates/hir-ty/src/layout.rs
@@ -1,5 +1,6 @@
 //! Compute the binary representation of a type
 
+use std::borrow::Cow;
 use std::fmt;
 
 use base_db::salsa::Cycle;
@@ -114,8 +115,8 @@ struct LayoutCx<'a> {
 impl<'a> LayoutCalculator for LayoutCx<'a> {
     type TargetDataLayoutRef = &'a TargetDataLayout;
 
-    fn delayed_bug(&self, txt: String) {
-        never!("{}", txt);
+    fn delayed_bug(&self, txt: impl Into<Cow<'static, str>>) {
+        never!("{}", txt.into());
     }
 
     fn current_data_layout(&self) -> &'a TargetDataLayout {
diff --git a/src/tools/rustfmt/src/parse/session.rs b/src/tools/rustfmt/src/parse/session.rs
index 60a89a5753641..cb46e65999df6 100644
--- a/src/tools/rustfmt/src/parse/session.rs
+++ b/src/tools/rustfmt/src/parse/session.rs
@@ -360,6 +360,7 @@ mod tests {
         }
 
         fn build_diagnostic(level: DiagnosticLevel, span: Option<MultiSpan>) -> DiagInner {
+            #[allow(rustc::untranslatable_diagnostic)] // no translation needed for empty string
             let mut diag = DiagInner::new(level, "");
             diag.messages.clear();
             if let Some(span) = span {
diff --git a/tests/ui-fulldeps/internal-lints/diagnostics.rs b/tests/ui-fulldeps/internal-lints/diagnostics.rs
index 6a978dabe628f..f73fdc0882ff9 100644
--- a/tests/ui-fulldeps/internal-lints/diagnostics.rs
+++ b/tests/ui-fulldeps/internal-lints/diagnostics.rs
@@ -14,8 +14,8 @@ extern crate rustc_session;
 extern crate rustc_span;
 
 use rustc_errors::{
-    AddToDiagnostic, Diag, EmissionGuarantee, DiagCtxt, IntoDiagnostic, Level,
-    SubdiagMessageOp,
+    AddToDiagnostic, DecorateLint, Diag, DiagCtxt, DiagInner, DiagMessage, EmissionGuarantee,
+    IntoDiagnostic, Level, SubdiagMessageOp,
 };
 use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_span::Span;
@@ -78,6 +78,31 @@ impl AddToDiagnostic for TranslatableInAddToDiagnostic {
     }
 }
 
+pub struct UntranslatableInDecorateLint;
+
+impl<'a> DecorateLint<'a, ()> for UntranslatableInDecorateLint {
+    fn decorate_lint<'b, >(self, diag: &'b mut Diag<'a, ()>) {
+        diag.note("untranslatable diagnostic");
+        //~^ ERROR diagnostics should be created using translatable messages
+    }
+
+    fn msg(&self) -> DiagMessage {
+        unreachable!();
+    }
+}
+
+pub struct TranslatableInDecorateLint;
+
+impl<'a> DecorateLint<'a, ()> for TranslatableInDecorateLint {
+    fn decorate_lint<'b>(self, diag: &'b mut Diag<'a, ()>) {
+        diag.note(crate::fluent_generated::no_crate_note);
+    }
+
+    fn msg(&self) -> DiagMessage {
+        unreachable!();
+    }
+}
+
 pub fn make_diagnostics<'a>(dcx: &'a DiagCtxt) {
     let _diag = dcx.struct_err(crate::fluent_generated::no_crate_example);
     //~^ ERROR diagnostics should only be created in `IntoDiagnostic`/`AddToDiagnostic` impls
@@ -87,9 +112,11 @@ pub fn make_diagnostics<'a>(dcx: &'a DiagCtxt) {
     //~^^ ERROR diagnostics should be created using translatable messages
 }
 
-// Check that `rustc_lint_diagnostics`-annotated functions aren't themselves linted.
+// Check that `rustc_lint_diagnostics`-annotated functions aren't themselves linted for
+// `diagnostic_outside_of_impl`.
 
 #[rustc_lint_diagnostics]
 pub fn skipped_because_of_annotation<'a>(dcx: &'a DiagCtxt) {
+    #[allow(rustc::untranslatable_diagnostic)]
     let _diag = dcx.struct_err("untranslatable diagnostic"); // okay!
 }
diff --git a/tests/ui-fulldeps/internal-lints/diagnostics.stderr b/tests/ui-fulldeps/internal-lints/diagnostics.stderr
index 5ddfdf32149aa..b8fbee1ff009c 100644
--- a/tests/ui-fulldeps/internal-lints/diagnostics.stderr
+++ b/tests/ui-fulldeps/internal-lints/diagnostics.stderr
@@ -16,8 +16,14 @@ error: diagnostics should be created using translatable messages
 LL |         diag.note("untranslatable diagnostic");
    |              ^^^^
 
+error: diagnostics should be created using translatable messages
+  --> $DIR/diagnostics.rs:85:14
+   |
+LL |         diag.note("untranslatable diagnostic");
+   |              ^^^^
+
 error: diagnostics should only be created in `IntoDiagnostic`/`AddToDiagnostic` impls
-  --> $DIR/diagnostics.rs:82:21
+  --> $DIR/diagnostics.rs:107:21
    |
 LL |     let _diag = dcx.struct_err(crate::fluent_generated::no_crate_example);
    |                     ^^^^^^^^^^
@@ -29,16 +35,16 @@ LL | #![deny(rustc::diagnostic_outside_of_impl)]
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: diagnostics should only be created in `IntoDiagnostic`/`AddToDiagnostic` impls
-  --> $DIR/diagnostics.rs:85:21
+  --> $DIR/diagnostics.rs:110:21
    |
 LL |     let _diag = dcx.struct_err("untranslatable diagnostic");
    |                     ^^^^^^^^^^
 
 error: diagnostics should be created using translatable messages
-  --> $DIR/diagnostics.rs:85:21
+  --> $DIR/diagnostics.rs:110:21
    |
 LL |     let _diag = dcx.struct_err("untranslatable diagnostic");
    |                     ^^^^^^^^^^
 
-error: aborting due to 5 previous errors
+error: aborting due to 6 previous errors
 
diff --git a/tests/ui/imports/append-import-suggestion.rs b/tests/ui/imports/append-import-suggestion.rs
new file mode 100644
index 0000000000000..6b75804b86fcb
--- /dev/null
+++ b/tests/ui/imports/append-import-suggestion.rs
@@ -0,0 +1,16 @@
+// https://github.com/rust-lang/rust/issues/114884
+
+mod mod1 {
+    pub trait TraitA {}
+}
+
+mod mod2 {
+    mod sub_mod {
+       use super::super::mod1::TraitA;
+    }
+}
+
+use mod2::{sub_mod::TraitA};
+//~^ ERROR: module `sub_mod` is private
+
+fn main() {}
diff --git a/tests/ui/imports/append-import-suggestion.stderr b/tests/ui/imports/append-import-suggestion.stderr
new file mode 100644
index 0000000000000..6d7b657f3d128
--- /dev/null
+++ b/tests/ui/imports/append-import-suggestion.stderr
@@ -0,0 +1,21 @@
+error[E0603]: module `sub_mod` is private
+  --> $DIR/append-import-suggestion.rs:13:12
+   |
+LL | use mod2::{sub_mod::TraitA};
+   |            ^^^^^^^ private module
+   |
+help: consider importing this trait instead:
+      mod1::TraitA
+  --> $DIR/append-import-suggestion.rs:13:12
+   |
+LL | use mod2::{sub_mod::TraitA};
+   |            ^^^^^^^^^^^^^^^
+note: the module `sub_mod` is defined here
+  --> $DIR/append-import-suggestion.rs:8:5
+   |
+LL |     mod sub_mod {
+   |     ^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0603`.
diff --git a/tests/ui/include-macros/parent_dir.rs b/tests/ui/include-macros/parent_dir.rs
new file mode 100644
index 0000000000000..4933ec4373c61
--- /dev/null
+++ b/tests/ui/include-macros/parent_dir.rs
@@ -0,0 +1,10 @@
+fn main() {
+    let _ = include_str!("include-macros/file.txt");            //~ ERROR couldn't read
+                                                                //~^HELP different directory
+    let _ = include_str!("hello.rs");                           //~ ERROR couldn't read
+                                                                //~^HELP different directory
+    let _ = include_bytes!("../../data.bin");                   //~ ERROR couldn't read
+                                                                //~^HELP different directory
+    let _ = include_str!("tests/ui/include-macros/file.txt");   //~ ERROR couldn't read
+                                                                //~^HELP different directory
+}
diff --git a/tests/ui/include-macros/parent_dir.stderr b/tests/ui/include-macros/parent_dir.stderr
new file mode 100644
index 0000000000000..3ec4c34763e4f
--- /dev/null
+++ b/tests/ui/include-macros/parent_dir.stderr
@@ -0,0 +1,50 @@
+error: couldn't read `$DIR/include-macros/file.txt`: No such file or directory (os error 2)
+  --> $DIR/parent_dir.rs:2:13
+   |
+LL |     let _ = include_str!("include-macros/file.txt");
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in the macro `include_str` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: there is a file with the same name in a different directory
+   |
+LL |     let _ = include_str!("file.txt");
+   |                          ~~~~~~~~~~
+
+error: couldn't read `$DIR/hello.rs`: No such file or directory (os error 2)
+  --> $DIR/parent_dir.rs:4:13
+   |
+LL |     let _ = include_str!("hello.rs");
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in the macro `include_str` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: there is a file with the same name in a different directory
+   |
+LL |     let _ = include_str!("../hello.rs");
+   |                          ~~~~~~~~~~~~~
+
+error: couldn't read `$DIR/../../data.bin`: No such file or directory (os error 2)
+  --> $DIR/parent_dir.rs:6:13
+   |
+LL |     let _ = include_bytes!("../../data.bin");
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in the macro `include_bytes` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: there is a file with the same name in a different directory
+   |
+LL |     let _ = include_bytes!("data.bin");
+   |                            ~~~~~~~~~~
+
+error: couldn't read `$DIR/tests/ui/include-macros/file.txt`: No such file or directory (os error 2)
+  --> $DIR/parent_dir.rs:8:13
+   |
+LL |     let _ = include_str!("tests/ui/include-macros/file.txt");
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: this error originates in the macro `include_str` (in Nightly builds, run with -Z macro-backtrace for more info)
+help: there is a file with the same name in a different directory
+   |
+LL |     let _ = include_str!("file.txt");
+   |                          ~~~~~~~~~~
+
+error: aborting due to 4 previous errors
+
diff --git a/tests/ui/instrument-coverage/bad-value.bad.stderr b/tests/ui/instrument-coverage/bad-value.bad.stderr
index b867d169dae5b..0411a1f98a3ee 100644
--- a/tests/ui/instrument-coverage/bad-value.bad.stderr
+++ b/tests/ui/instrument-coverage/bad-value.bad.stderr
@@ -1,2 +1,2 @@
-error: incorrect value `bad-value` for codegen option `instrument-coverage` - `all` (default), `branch`, `except-unused-generics`, `except-unused-functions`, or `off` was expected
+error: incorrect value `bad-value` for codegen option `instrument-coverage` - either a boolean (`yes`, `no`, `on`, `off`, etc) or (unstable) one of `branch`, `except-unused-generics`, `except-unused-functions` was expected
 
diff --git a/tests/ui/instrument-coverage/bad-value.blank.stderr b/tests/ui/instrument-coverage/bad-value.blank.stderr
index e7122fb61cdfc..b3a8e7cf94784 100644
--- a/tests/ui/instrument-coverage/bad-value.blank.stderr
+++ b/tests/ui/instrument-coverage/bad-value.blank.stderr
@@ -1,2 +1,2 @@
-error: incorrect value `` for codegen option `instrument-coverage` - `all` (default), `branch`, `except-unused-generics`, `except-unused-functions`, or `off` was expected
+error: incorrect value `` for codegen option `instrument-coverage` - either a boolean (`yes`, `no`, `on`, `off`, etc) or (unstable) one of `branch`, `except-unused-generics`, `except-unused-functions` was expected
 
diff --git a/tests/ui/lint/lint-qualification.fixed b/tests/ui/lint/lint-qualification.fixed
index ab450f8b7347d..2b1f8b591752a 100644
--- a/tests/ui/lint/lint-qualification.fixed
+++ b/tests/ui/lint/lint-qualification.fixed
@@ -24,6 +24,9 @@ fn main() {
     use std::fmt;
     let _: fmt::Result = Ok(()); //~ ERROR: unnecessary qualification
 
+    let _ = <bool as Default>::default(); // issue #121999
+    //~^ ERROR: unnecessary qualification
+
     macro_rules! m { ($a:ident, $b:ident) => {
         $crate::foo::bar(); // issue #37357
         ::foo::bar(); // issue #38682
diff --git a/tests/ui/lint/lint-qualification.rs b/tests/ui/lint/lint-qualification.rs
index 84a36f509eb9e..002fdbf7724a7 100644
--- a/tests/ui/lint/lint-qualification.rs
+++ b/tests/ui/lint/lint-qualification.rs
@@ -24,6 +24,9 @@ fn main() {
     use std::fmt;
     let _: std::fmt::Result = Ok(()); //~ ERROR: unnecessary qualification
 
+    let _ = <bool as ::std::default::Default>::default(); // issue #121999
+    //~^ ERROR: unnecessary qualification
+
     macro_rules! m { ($a:ident, $b:ident) => {
         $crate::foo::bar(); // issue #37357
         ::foo::bar(); // issue #38682
diff --git a/tests/ui/lint/lint-qualification.stderr b/tests/ui/lint/lint-qualification.stderr
index 45e1525f4bf8c..8dddcf23f7575 100644
--- a/tests/ui/lint/lint-qualification.stderr
+++ b/tests/ui/lint/lint-qualification.stderr
@@ -87,5 +87,17 @@ LL -     let _: std::fmt::Result = Ok(());
 LL +     let _: fmt::Result = Ok(());
    |
 
-error: aborting due to 7 previous errors
+error: unnecessary qualification
+  --> $DIR/lint-qualification.rs:27:13
+   |
+LL |     let _ = <bool as ::std::default::Default>::default(); // issue #121999
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: remove the unnecessary path segments
+   |
+LL -     let _ = <bool as ::std::default::Default>::default(); // issue #121999
+LL +     let _ = <bool as Default>::default(); // issue #121999
+   |
+
+error: aborting due to 8 previous errors
 
diff --git a/tests/ui/macros/macros-nonfatal-errors.stderr b/tests/ui/macros/macros-nonfatal-errors.stderr
index ca373ea6cd9e4..2b3cff9891e1e 100644
--- a/tests/ui/macros/macros-nonfatal-errors.stderr
+++ b/tests/ui/macros/macros-nonfatal-errors.stderr
@@ -200,7 +200,7 @@ error: argument must be a string literal
 LL |     include_str!(invalid);
    |                  ^^^^^^^
 
-error: couldn't read $DIR/i'd be quite surprised if a file with this name existed: $FILE_NOT_FOUND_MSG (os error 2)
+error: couldn't read `$DIR/i'd be quite surprised if a file with this name existed`: No such file or directory (os error 2)
   --> $DIR/macros-nonfatal-errors.rs:113:5
    |
 LL |     include_str!("i'd be quite surprised if a file with this name existed");
@@ -214,7 +214,7 @@ error: argument must be a string literal
 LL |     include_bytes!(invalid);
    |                    ^^^^^^^
 
-error: couldn't read $DIR/i'd be quite surprised if a file with this name existed: $FILE_NOT_FOUND_MSG (os error 2)
+error: couldn't read `$DIR/i'd be quite surprised if a file with this name existed`: No such file or directory (os error 2)
   --> $DIR/macros-nonfatal-errors.rs:115:5
    |
 LL |     include_bytes!("i'd be quite surprised if a file with this name existed");
diff --git a/tests/ui/test-attrs/terse.rs b/tests/ui/test-attrs/terse.rs
new file mode 100644
index 0000000000000..ab9d5cc19bd6c
--- /dev/null
+++ b/tests/ui/test-attrs/terse.rs
@@ -0,0 +1,125 @@
+//@ compile-flags: --test
+//@ run-fail
+//@ run-flags: --test-threads=1 --quiet
+//@ check-run-results
+//@ exec-env:RUST_BACKTRACE=0
+//@ normalize-stdout-test "finished in \d+\.\d+s" -> "finished in $$TIME"
+//@ ignore-emscripten no threads support
+//@ needs-unwind
+
+#[test]
+fn abc() {
+    panic!();
+}
+
+#[test]
+fn foo() {
+    panic!();
+}
+
+#[test]
+fn foo2() {
+    panic!();
+}
+
+// run a whole bunch of tests so we can see what happens when we go over 88 columns
+#[test] fn f0() {}
+#[test] fn f1() {}
+#[test] fn f2() {}
+#[test] fn f3() {}
+#[test] fn f4() {}
+#[test] fn f5() {}
+#[test] fn f6() {}
+#[test] fn f7() {}
+#[test] fn f8() {}
+#[test] fn f9() {}
+#[test] fn f10() {}
+#[test] fn f11() {}
+#[test] fn f12() {}
+#[test] fn f13() {}
+#[test] fn f14() {}
+#[test] fn f15() {}
+#[test] fn f16() {}
+#[test] fn f17() {}
+#[test] fn f18() {}
+#[test] fn f19() {}
+#[test] fn f20() {}
+#[test] fn f21() {}
+#[test] fn f22() {}
+#[test] fn f23() {}
+#[test] fn f24() {}
+#[test] fn f25() {}
+#[test] fn f26() {}
+#[test] fn f27() {}
+#[test] fn f28() {}
+#[test] fn f29() {}
+#[test] fn f30() {}
+#[test] fn f31() {}
+#[test] fn f32() {}
+#[test] fn f33() {}
+#[test] fn f34() {}
+#[test] fn f35() {}
+#[test] fn f36() {}
+#[test] fn f37() {}
+#[test] fn f38() {}
+#[test] fn f39() {}
+#[test] fn f40() {}
+#[test] fn f41() {}
+#[test] fn f42() {}
+#[test] fn f43() {}
+#[test] fn f44() {}
+#[test] fn f45() {}
+#[test] fn f46() {}
+#[test] fn f47() {}
+#[test] fn f48() {}
+#[test] fn f49() {}
+#[test] fn f50() {}
+#[test] fn f51() {}
+#[test] fn f52() {}
+#[test] fn f53() {}
+#[test] fn f54() {}
+#[test] fn f55() {}
+#[test] fn f56() {}
+#[test] fn f57() {}
+#[test] fn f58() {}
+#[test] fn f59() {}
+#[test] fn f60() {}
+#[test] fn f61() {}
+#[test] fn f62() {}
+#[test] fn f63() {}
+#[test] fn f64() {}
+#[test] fn f65() {}
+#[test] fn f66() {}
+#[test] fn f67() {}
+#[test] fn f68() {}
+#[test] fn f69() {}
+#[test] fn f70() {}
+#[test] fn f71() {}
+#[test] fn f72() {}
+#[test] fn f73() {}
+#[test] fn f74() {}
+#[test] fn f75() {}
+#[test] fn f76() {}
+#[test] fn f77() {}
+#[test] fn f78() {}
+#[test] fn f79() {}
+#[test] fn f80() {}
+#[test] fn f81() {}
+#[test] fn f82() {}
+#[test] fn f83() {}
+#[test] fn f84() {}
+#[test] fn f85() {}
+#[test] fn f86() {}
+#[test] fn f87() {}
+#[test] fn f88() {}
+#[test] fn f89() {}
+#[test] fn f90() {}
+#[test] fn f91() {}
+#[test] fn f92() {}
+#[test] fn f93() {}
+#[test] fn f94() {}
+#[test] fn f95() {}
+#[test] fn f96() {}
+#[test] fn f97() {}
+#[test] fn f98() {}
+#[test] fn f99() {}
diff --git a/tests/ui/test-attrs/terse.run.stdout b/tests/ui/test-attrs/terse.run.stdout
new file mode 100644
index 0000000000000..2b361361ae888
--- /dev/null
+++ b/tests/ui/test-attrs/terse.run.stdout
@@ -0,0 +1,31 @@
+
+running 103 tests
+abc --- FAILED
+....................................................................................... 88/103
+............. 101/103
+foo --- FAILED
+foo2 --- FAILED
+
+failures:
+
+---- abc stdout ----
+thread 'abc' panicked at $DIR/terse.rs:12:5:
+explicit panic
+note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
+
+---- foo stdout ----
+thread 'foo' panicked at $DIR/terse.rs:17:5:
+explicit panic
+
+---- foo2 stdout ----
+thread 'foo2' panicked at $DIR/terse.rs:22:5:
+explicit panic
+
+
+failures:
+    abc
+    foo
+    foo2
+
+test result: FAILED. 100 passed; 3 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
+