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Cranelift: panic calculating timing total #12692
Description
Steps to Reproduce
Unclear, this is a crash we saw in our telemetry at https://zed.dev. I see that there's a debug_assert that the passes should be in the right order, but in a release build the panic happens later.
overflow when subtracting durations
core::time::impl$3::sub (time.rs:1164)
cranelift_codegen::timing::enabled::impl$0::total::closure$0 (timing.rs:174)
core::ops::function::impls::impl$4::call_once (function.rs:310)
core::option::Option::map (option.rs:1165)
core::iter::adapters::map::impl$2::next (map.rs:107)
core::time::impl$10::sum (time.rs:1259)
core::iter::traits::iterator::Iterator::sum (iterator.rs:3581)
cranelift_codegen::timing::enabled::PassTimes::total (timing.rs:174)
wasmtime_cranelift::compiler::impl$3::compile_function (compiler.rs:284)
wasmtime::compile::impl$4::collect_inputs_in_translations::closure$0 (compile.rs:490)
core::ops::function::FnOnce::call_once<T> (function.rs:250)
alloc::boxed::impl$31::call_once (boxed.rs:2206)
wasmtime::compile::compile_required_builtins::closure$1 (compile.rs:610)
wasmtime::engine::impl$2::run_maybe_parallel::closure$0 (engine.rs:183)
core::ops::function::impls::impl$1::call_mut (function.rs:274)
core::ops::function::impls::impl$4::call_once (function.rs:310)
core::option::Option::map (option.rs:1165)
core::iter::adapters::map::impl$2::next (map.rs:107)
rayon::iter::plumbing::Folder::consume_iter (mod.rs:173)
Expected Results
No panic
Actual Results
Panic
Versions and Environment
Cranelift version or commit: 33.0.2
Operating system: Windows
Architecture: x86
Extra Info
Anything else you'd like to add?
Activity
Cranelift: robustify timing infrastructure against mis-use and/or sys…
Cranelift: robustify timing infrastructure against mis-use and/or sys…
fitzgen commentedon Mar 26, 2026
Fixed in #12709 I believe; reopen if not.
benbrandt commentedon May 4, 2026
We are seeing this on the v36 LTS branch. Any chance this could be backported?
alexcrichton commentedon May 4, 2026
You can find more docs on backporting here, but tl;dr; yes this is fine to backport. Backports for bug fixes (as opposed to security fixes) are on a best-effort basis and one that we accept external PRs for. @benbrandt would you be up for sending a PR to the
release-36.0.0branch?benbrandt commentedon May 5, 2026
Sure thing! Made it here: #13273
Let me know if you need anything else
Cranelift: robustify timing infrastructure against mis-use and/or sys…