Re: zsh malloc/heap corruption

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Fri, Sep 26, 2025 at 8:12 PM Anthony Heading <ajrh@xxxxxxxx> wrote:
>
> Attached is a mechanically-reduced test case which I hope still reflects the bug I'm encountering, some kind of malloc/heap corruption.

This doesn't crash for me using a fresh build from git on Ubuntu
22.04, unless exiting 125 because there's a race condition creating
the FIFO counts as a crash,.

On the other hand, it doesn't DO anything either, except hang with 5
zsh processes and one grep still running.  I've tried running it with
zsh -f, zsh -ifc, and from a PS1 prompt, and it always behaves that
way.

Src/zsh -fx /tmp/crash.zsh
+/tmp/crash.zsh:3> zmodload zsh/system
+/tmp/crash.zsh:89> count=100
+/tmp/crash.zsh:91> spawn_subprocess
+spawn_subprocess:2> local parallel_count=2
+spawn_subprocess:4> launch_instance
+/tmp/crash.zsh:91> grep -v '^\+'
+spawn_subprocess:4> launch_instance
+spawn_subprocess:7> wait

zsh-5.9 gets a little further, hits the "wait" 3 times before hanging,
but that's all.

What's expected to happen?  What zsh version and OS are you using?

On MacOS I do see "exit 137" every now and then, which is odd because
that's the exit code for "kill -9".