[Nix-dev] Re: Build job nixpkgsTrunk succeeded

[Ludovic Courtès]

Hello,

Eelco Dolstra <e.dolstra at tudelft.nl>
writes:

> Note the "Broken pipe" message from M4.  So it's that bug again :-)
>
> I experimented with SIGPIPE a bit more and it turns out that this Nix expression
> randomly fails (i.e. sometimes it says "Broken pipe" and sometimes it doesn't):
>
>   dummy = runCommand "foo" {} ''
>     seq 10000 | tee foo | head > /dev/null
>   '';
>
> The root cause is that Nix sets the SIGPIPE handler to SIG_IGN, which is
> inherited by all the children.  I don't remember *why* we're ignoring SIGPIPE,
> but there was probably a good reason ;-)  So I've committed a fix that sets
> SIGPIPE to SIG_DFL when running the builder.

Good to see that you found out!  Let's cross fingers and hope it will
remove a class of mysterious bugs.

BTW, was it on x86-64?  Bison's test suite appears to run flawlessly
here on i686.

Thanks!

Ludo'.