comptime fn error: suggest wrapping in const block by mejrs · Pull Request #163772 · rust-lang/rust

mejrs · 2026-10-04T22:24:50Z

It won't always be correct, since all values captured by a const block must also be determined at compile time, but it should usually work or be a step in the right direction

rustbot · 2026-10-04T22:24:55Z

r? @nnethercote

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nnethercote · 2026-10-06T04:30:01Z

@bors r+ rollup

rust-bors · 2026-10-06T04:30:04Z

📌 Commit 18ecbb5 has been approved by nnethercote

It is now in the queue for this repository.

comptime fn error: suggest wrapping in const block It won't always be correct, since all values captured by a const block must also be determined at compile time, but it should usually work or be a step in the right direction

Rollup of 3 pull requests Successful merges: - #163809 (Adjust the adjustment to wasi TLS to no longer adjust) - #163348 (perf:cache FFI safety results in improper_ctypes lint) - #163772 (comptime fn error: suggest wrapping in const block)

jhpratt · 2026-10-06T05:03:28Z

@bors r- #163858 (comment)

To only update this specific test, also pass `--test-args attributes/doc_examples/rustc_comptime.rs`

error: 1 errors occurred comparing output.
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage1/bin/rustc" "/checkout/tests/ui/attributes/doc_examples/rustc_comptime.rs" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage1" "--target=x86_64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/x86_64-unknown-linux-gnu/test/ui/attributes/doc_examples/rustc_comptime" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "--edition=2015" "--crate-type" "lib" "-Z" "ui-testing=no"
stdout: none
--- stderr -------------------------------
error: comptime functions can only be called at compile time
##[error]  --> /checkout/tests/ui/attributes/doc_examples/rustc_comptime.rs:10:5
   |

rust-bors · 2026-10-06T05:03:37Z

This pull request was unapproved.

This PR was contained in a rollup (#163858), which was unapproved.

View changes since this unapproval

It won't always be correct, since all values captured by a const block must also be determined at compile time, but it should usually work or be a step in the right direction

rustbot · 2026-10-08T12:04:45Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

mejrs · 2026-10-08T12:08:51Z

@bors r=nnethercote

rust-bors · 2026-10-08T12:08:54Z

📌 Commit 13703b5 has been tentatively approved by nnethercote

It will be put into the queue for this repository once PR CI succeeds.

comptime fn error: suggest wrapping in const block It won't always be correct, since all values captured by a const block must also be determined at compile time, but it should usually work or be a step in the right direction

…uwer Rollup of 12 pull requests Successful merges: - #163462 (Fix COFF renaming of decorated (stdcall/fastcall/vectorcall) exports) - #163855 (Include enclosing item's context on const errors) - #163861 (Run LLDB debuginfo tests on `x86_64-mingw`) - #161201 (Speed up tidy again) - #163538 (Add `rustc::missing_generic_type_visitable` lint) - #163617 (mips: make `Complex<T>` ABI match GCC) - #163772 (comptime fn error: suggest wrapping in const block) - #163832 (reject non-async coroutine closures as async callables) - #163958 (only make `RustaceansAreAwesome` satisfy trait clauses) - #163974 (Condense AdtDef lang item checks into one match) - #163979 (Add `bf16` to arm features) - #163989 (Revert "compiletest: stream output of executor process when --no-capture is set") Failed merges: - #163972 (const-eval: ICE when we hit a non-const fn)

…uwer Rollup of 19 pull requests Successful merges: - #156112 (Distinguish `repr(C)` ZSTs from others in ABI computation) - #157941 (Deny partial `-Z stack-protector` by default in all editions) - #163462 (Fix COFF renaming of decorated (stdcall/fastcall/vectorcall) exports) - #163855 (Include enclosing item's context on const errors) - #163861 (Run LLDB debuginfo tests on `x86_64-mingw`) - #163913 ( Silence redundant failed obligations on the same statement) - #161201 (Speed up tidy again) - #163380 (Tweak "name not found" resolution error when it happens from within a derive expansion) - #163538 (Add `rustc::missing_generic_type_visitable` lint) - #163617 (mips: make `Complex<T>` ABI match GCC) - #163772 (comptime fn error: suggest wrapping in const block) - #163813 (use pre-borrowck typing env for early MIR validation) - #163924 (replace instances of NonNull::new(&mut x).expect("...") with NonNull::from_mut) - #163958 (only make `RustaceansAreAwesome` satisfy trait clauses) - #163960 (vexos: clear .bss from assembly) - #163974 (Condense AdtDef lang item checks into one match) - #163979 (Add `bf16` to arm features) - #163989 (Revert "compiletest: stream output of executor process when --no-capture is set") - #163995 (m68k-unknown-none-elf: Remove code model) Failed merges: - #163832 (reject non-async coroutine closures as async callables) - #163972 (const-eval: ICE when we hit a non-const fn)

Rollup merge of #163772 - mejrs:comptime_error, r=nnethercote comptime fn error: suggest wrapping in const block It won't always be correct, since all values captured by a const block must also be determined at compile time, but it should usually work or be a step in the right direction

…uwer Rollup of 19 pull requests Successful merges: - rust-lang/rust#156112 (Distinguish `repr(C)` ZSTs from others in ABI computation) - rust-lang/rust#157941 (Deny partial `-Z stack-protector` by default in all editions) - rust-lang/rust#163462 (Fix COFF renaming of decorated (stdcall/fastcall/vectorcall) exports) - rust-lang/rust#163855 (Include enclosing item's context on const errors) - rust-lang/rust#163861 (Run LLDB debuginfo tests on `x86_64-mingw`) - rust-lang/rust#163913 ( Silence redundant failed obligations on the same statement) - rust-lang/rust#161201 (Speed up tidy again) - rust-lang/rust#163380 (Tweak "name not found" resolution error when it happens from within a derive expansion) - rust-lang/rust#163538 (Add `rustc::missing_generic_type_visitable` lint) - rust-lang/rust#163617 (mips: make `Complex<T>` ABI match GCC) - rust-lang/rust#163772 (comptime fn error: suggest wrapping in const block) - rust-lang/rust#163813 (use pre-borrowck typing env for early MIR validation) - rust-lang/rust#163924 (replace instances of NonNull::new(&mut x).expect("...") with NonNull::from_mut) - rust-lang/rust#163958 (only make `RustaceansAreAwesome` satisfy trait clauses) - rust-lang/rust#163960 (vexos: clear .bss from assembly) - rust-lang/rust#163974 (Condense AdtDef lang item checks into one match) - rust-lang/rust#163979 (Add `bf16` to arm features) - rust-lang/rust#163989 (Revert "compiletest: stream output of executor process when --no-capture is set") - rust-lang/rust#163995 (m68k-unknown-none-elf: Remove code model) Failed merges: - rust-lang/rust#163832 (reject non-async coroutine closures as async callables) - rust-lang/rust#163972 (const-eval: ICE when we hit a non-const fn)

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Oct 4, 2026

rustbot assigned nnethercote Oct 4, 2026

mejrs force-pushed the comptime_error branch from 78069be to 18ecbb5 Compare October 4, 2026 22:32

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jhpratt mentioned this pull request Oct 6, 2026

Rollup of 3 pull requests #163858

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rust-bors Bot added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Oct 6, 2026

comptime fn error: suggest wrapping in const block

13703b5

It won't always be correct, since all values captured by a const block must also be determined at compile time, but it should usually work or be a step in the right direction

mejrs force-pushed the comptime_error branch from 18ecbb5 to 13703b5 Compare October 8, 2026 12:04

rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Oct 8, 2026

JonathanBrouwer mentioned this pull request Oct 8, 2026

Rollup of 12 pull requests #163993

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JonathanBrouwer mentioned this pull request Oct 8, 2026

Rollup of 19 pull requests #164005

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rust-bors Bot merged commit f90de16 into rust-lang:main Oct 8, 2026
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rustbot added this to the 1.101.0 milestone Oct 8, 2026

github-actions Bot mentioned this pull request Oct 9, 2026

Toolchain upgrade to nightly-2026-10-09 flux-rs/flux#1811

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comptime fn error: suggest wrapping in const block - #163772

comptime fn error: suggest wrapping in const block#163772
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