Bug#964541: make: Regression on s390x, echo EPERM, caused by posix_spawn change

[ adding debian-s390 to Cc ]

On Wed, Jul 08, 2020 at 01:42:33PM +0200, Julian Andres Klode wrote:
> Package: make-dfsg
> Version: 4.3-4
> Severity: serious
> Tags: patch
> User: [email protected]
> Usertags: origin-ubuntu groovy ubuntu-patch
> 
> In Ubuntu, the attached patch was applied to achieve the following:
> 
> The autopkgtests for flatpak-builder/s390x where failing with
> 
>   echo Building
>   make: echo: Operation not permitted
>   make: *** [Makefile:2: all] Error 127
> 
> git bisect lead to
> 
> commit 749a54d7a458dc6779936138caf40ce600a80052 (refs/bisect/bad)
> Author: Aron Barath <[email protected]>
> Date:   Mon Jul 9 09:05:31 2018 +0200
> 
>     * job.c (child_execute_job): Prefer posix_spawn() over fork()/exec()
> 
> and I can confirm that disabling posix_spawn makes the autopkgtest
> work again.
> 
> Earlier research also indicated that this is a heisenbug, if I try
> to print to stderr before printing to stdout, no issue occurs.
> 
>   * Pass --disable-posix-spawn to configure, as use of posix_spawn()
>     causes a regression on s390x, with commands getting EPERM when
>     writing to stdout.
>...

Is posix_spawn() broken on s390x, or is this a bug in make?

The former would be really worrisome for a release architecture.

cu
Adrian