Stream: git-wasmtime

Topic: wasmtime / PR #10974 Fix ASAN in combination with throw i...

Wasmtime GitHub notifications bot (Jun 07 2025 at 00:20):

alexcrichton opened PR #10974 from alexcrichton:asan-new-intrinsic to bytecodealliance:main:

Prior to this commit locally I would see a nondeterministic crash when executing:

RUSTFLAGS=-Zsanitizer=address \
  cargo +nightly run --release test filetests

The crash has a scary-looking internal assertion within the ASAN runtime itself and local debugging seems to show that threads are required to reproduce this and it's nondeterministic. I don't know why CI is currently passing on all PRs when this is failing so frequently for myself locally.

In any case it seems like there's a magical ASAN intrinsic to call before noreturn things which I think is intended for thread-stopping events which isn't a great fit for exceptions here but it seems to resolve the crash.

Basically I have no idea why things crash locally, what this new function does, nor why it fixes things. I am but a slave to the CI gods in an attempt to make it so our CI is more reliable.

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Wasmtime GitHub notifications bot (Jun 07 2025 at 00:20):

alexcrichton requested pchickey for a review on PR #10974.

Wasmtime GitHub notifications bot (Jun 07 2025 at 00:20):

alexcrichton requested wasmtime-core-reviewers for a review on PR #10974.

Wasmtime GitHub notifications bot (Jun 07 2025 at 00:27):

alexcrichton updated PR #10974.

Wasmtime GitHub notifications bot (Jun 07 2025 at 00:31):

cfallin submitted PR review:

Thanks for catching this!

Wasmtime GitHub notifications bot (Jun 07 2025 at 00:32):

cfallin has enabled auto merge for PR #10974.

Wasmtime GitHub notifications bot (Jun 07 2025 at 01:01):

cfallin merged PR #10974.

Last updated: Dec 06 2025 at 06:05 UTC