Simplify query stack printing - #162946
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rust-bors[bot] merged 1 commit intoSep 19, 2026
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Currently it uses `eprintln!` for the "query stack during panic" header
and "end of query stack" footer and
`struct_failure_note(..).with_span(..).emit()` for the stack frames. The
difference is curious.
Looking more closely:
- failure notes lack a leading label (e.g. no "note: ");
- although the failure note is given a span, the span never renders
because the `AnnotateSnippetEmitter` used for the query stack has an
empty source map field;
- the JSON emitter is never involved here.
Therefore, the only difference between using `struct_failure_note` and
`eprintln!` is that the former prints in bold. But boldness for frames
isn't important; indeed, normal backtrace frames don't use bold.
So the commit changes query stack frame printing to use `eprintln!`,
removes some now unnecessary `dcx` arguments, and also removes
`struct_failure_note`. That leaves "For more information about an error,
try `rustc --explain {}`" as the only use of `FailureNote`.
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JonathanBrouwer
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to JonathanBrouwer/rust
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Sep 18, 2026
…rinting, r=estebank
Simplify query stack printing
Currently it uses `eprintln!` for the "query stack during panic" header and "end of query stack" footer and
`struct_failure_note(..).with_span(..).emit()` for the stack frames. The difference is curious.
Looking more closely:
- failure notes lack a leading label (e.g. no "note: ");
- although the failure note is given a span, the span never renders because the `AnnotateSnippetEmitter` used for the query stack has an empty source map field;
- the JSON emitter is never involved here.
Therefore, the only difference between using `struct_failure_note` and `eprintln!` is that the former prints in bold. But boldness for frames isn't important; indeed, normal backtrace frames don't use bold.
So the commit changes query stack frame printing to use `eprintln!`, removes some now unnecessary `dcx` arguments, and also removes `struct_failure_note`. That leaves "For more information about an error, try `rustc --explain {}`" as the only use of `FailureNote`.
r? @estebank
JonathanBrouwer
added a commit
to JonathanBrouwer/rust
that referenced
this pull request
Sep 18, 2026
…rinting, r=estebank
Simplify query stack printing
Currently it uses `eprintln!` for the "query stack during panic" header and "end of query stack" footer and
`struct_failure_note(..).with_span(..).emit()` for the stack frames. The difference is curious.
Looking more closely:
- failure notes lack a leading label (e.g. no "note: ");
- although the failure note is given a span, the span never renders because the `AnnotateSnippetEmitter` used for the query stack has an empty source map field;
- the JSON emitter is never involved here.
Therefore, the only difference between using `struct_failure_note` and `eprintln!` is that the former prints in bold. But boldness for frames isn't important; indeed, normal backtrace frames don't use bold.
So the commit changes query stack frame printing to use `eprintln!`, removes some now unnecessary `dcx` arguments, and also removes `struct_failure_note`. That leaves "For more information about an error, try `rustc --explain {}`" as the only use of `FailureNote`.
r? @estebank
rust-bors Bot
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that referenced
this pull request
Sep 18, 2026
…uwer Rollup of 20 pull requests Successful merges: - #160401 (sparc: make ABI consistent with clang) - #162715 (don't calculate dtors if the self ty has impossible bounds) - #162740 (stdarch subtree update) - #162824 (link Enzyme and the offload with in-tree lld if possible) - #162946 (Simplify query stack printing) - #161005 (fix: unfulfilled nested dead code lint) - #161246 (Normalize non-rigid aliases in ty_known_to_outlive) - #161803 (Fix docs of make_ascii_lowercase/make_ascii_upercase) - #162256 (Add mentions to sync back `RELEASES.md` to the `main` branch) - #162661 (simplify `Target::GenericParam`) - #162666 (Tidy footnote in `platform-support.md`) - #162803 (docs(num): add documentation for `NonZero::from_str`) - #162879 (use u64 limbs in core::num::bignum) - #162903 (PassWrapper: adapt to LLVM reading exception model from module flag) - #162905 (c-variadic: add checks for windows i686) - #162906 (Move more `rustdoc-html` tests in the right location) - #162922 (An assortment of polonius tweaks) - #162929 (Update unicode_data to Unicode version 18.0.0) - #162930 (Use niche length type for strlen to guarantee `isize::MAX` bound) - #162960 (Guard types with unstable `Allocator` params ahead of partial stabilization)
rust-bors Bot
pushed a commit
that referenced
this pull request
Sep 18, 2026
…uwer Rollup of 19 pull requests Successful merges: - #160401 (sparc: make ABI consistent with clang) - #162715 (don't calculate dtors if the self ty has impossible bounds) - #162740 (stdarch subtree update) - #162946 (Simplify query stack printing) - #161005 (fix: unfulfilled nested dead code lint) - #161246 (Normalize non-rigid aliases in ty_known_to_outlive) - #161803 (Fix docs of make_ascii_lowercase/make_ascii_upercase) - #162256 (Add mentions to sync back `RELEASES.md` to the `main` branch) - #162661 (simplify `Target::GenericParam`) - #162666 (Tidy footnote in `platform-support.md`) - #162803 (docs(num): add documentation for `NonZero::from_str`) - #162879 (use u64 limbs in core::num::bignum) - #162903 (PassWrapper: adapt to LLVM reading exception model from module flag) - #162905 (c-variadic: add checks for windows i686) - #162906 (Move more `rustdoc-html` tests in the right location) - #162922 (An assortment of polonius tweaks) - #162929 (Update unicode_data to Unicode version 18.0.0) - #162930 (Use niche length type for strlen to guarantee `isize::MAX` bound) - #162960 (Guard types with unstable `Allocator` params ahead of partial stabilization)
rust-bors Bot
pushed a commit
that referenced
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Sep 18, 2026
…uwer Rollup of 19 pull requests Successful merges: - #160401 (sparc: make ABI consistent with clang) - #162715 (don't calculate dtors if the self ty has impossible bounds) - #162740 (stdarch subtree update) - #162946 (Simplify query stack printing) - #161005 (fix: unfulfilled nested dead code lint) - #161246 (Normalize non-rigid aliases in ty_known_to_outlive) - #161803 (Fix docs of make_ascii_lowercase/make_ascii_upercase) - #162256 (Add mentions to sync back `RELEASES.md` to the `main` branch) - #162661 (simplify `Target::GenericParam`) - #162666 (Tidy footnote in `platform-support.md`) - #162803 (docs(num): add documentation for `NonZero::from_str`) - #162879 (use u64 limbs in core::num::bignum) - #162903 (PassWrapper: adapt to LLVM reading exception model from module flag) - #162905 (c-variadic: add checks for windows i686) - #162906 (Move more `rustdoc-html` tests in the right location) - #162922 (An assortment of polonius tweaks) - #162929 (Update unicode_data to Unicode version 18.0.0) - #162930 (Use niche length type for strlen to guarantee `isize::MAX` bound) - #162960 (Guard types with unstable `Allocator` params ahead of partial stabilization)
rust-bors Bot
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Sep 19, 2026
Rollup merge of #162946 - nnethercote:simplify-query-stack-printing, r=estebank Simplify query stack printing Currently it uses `eprintln!` for the "query stack during panic" header and "end of query stack" footer and `struct_failure_note(..).with_span(..).emit()` for the stack frames. The difference is curious. Looking more closely: - failure notes lack a leading label (e.g. no "note: "); - although the failure note is given a span, the span never renders because the `AnnotateSnippetEmitter` used for the query stack has an empty source map field; - the JSON emitter is never involved here. Therefore, the only difference between using `struct_failure_note` and `eprintln!` is that the former prints in bold. But boldness for frames isn't important; indeed, normal backtrace frames don't use bold. So the commit changes query stack frame printing to use `eprintln!`, removes some now unnecessary `dcx` arguments, and also removes `struct_failure_note`. That leaves "For more information about an error, try `rustc --explain {}`" as the only use of `FailureNote`. r? @estebank
pull Bot
pushed a commit
to LeeeeeeM/miri
that referenced
this pull request
Sep 19, 2026
…uwer Rollup of 19 pull requests Successful merges: - rust-lang/rust#160401 (sparc: make ABI consistent with clang) - rust-lang/rust#162715 (don't calculate dtors if the self ty has impossible bounds) - rust-lang/rust#162740 (stdarch subtree update) - rust-lang/rust#162946 (Simplify query stack printing) - rust-lang/rust#161005 (fix: unfulfilled nested dead code lint) - rust-lang/rust#161246 (Normalize non-rigid aliases in ty_known_to_outlive) - rust-lang/rust#161803 (Fix docs of make_ascii_lowercase/make_ascii_upercase) - rust-lang/rust#162256 (Add mentions to sync back `RELEASES.md` to the `main` branch) - rust-lang/rust#162661 (simplify `Target::GenericParam`) - rust-lang/rust#162666 (Tidy footnote in `platform-support.md`) - rust-lang/rust#162803 (docs(num): add documentation for `NonZero::from_str`) - rust-lang/rust#162879 (use u64 limbs in core::num::bignum) - rust-lang/rust#162903 (PassWrapper: adapt to LLVM reading exception model from module flag) - rust-lang/rust#162905 (c-variadic: add checks for windows i686) - rust-lang/rust#162906 (Move more `rustdoc-html` tests in the right location) - rust-lang/rust#162922 (An assortment of polonius tweaks) - rust-lang/rust#162929 (Update unicode_data to Unicode version 18.0.0) - rust-lang/rust#162930 (Use niche length type for strlen to guarantee `isize::MAX` bound) - rust-lang/rust#162960 (Guard types with unstable `Allocator` params ahead of partial stabilization)
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Currently it uses
eprintln!for the "query stack during panic" header and "end of query stack" footer andstruct_failure_note(..).with_span(..).emit()for the stack frames. The difference is curious.Looking more closely:
AnnotateSnippetEmitterused for the query stack has an empty source map field;Therefore, the only difference between using
struct_failure_noteandeprintln!is that the former prints in bold. But boldness for frames isn't important; indeed, normal backtrace frames don't use bold.So the commit changes query stack frame printing to use
eprintln!, removes some now unnecessarydcxarguments, and also removesstruct_failure_note. That leaves "For more information about an error, tryrustc --explain {}" as the only use ofFailureNote.r? @estebank