pipe hang issue when running as SYSTEM

[Takashi Yano]

On Thu, 24 Mar 2022 20:42:50 -0700 (PDT)
Jeremy Drake wrote:
> On Tue, 22 Mar 2022, Takashi Yano wrote:
> 
> > > Thanks for the report. This is expected problem as mentioned
> > > in b531d6b commit message. However, I could not imagin the
> > > situation that the service has multiple writer for the pipe
> > > and one of them is a non-cygwin app.
> > >
> > > Question is: Does the docker invoke the command using SYSTEM
> > > account? Or is the processes in docker determined as running
> > > as a service?
> >
> > I confirmed the processes in Windows docker are running as
> > well_known_service_sid. Let me consider a while.
> >
> 
> Just got another report to MSYS2 of this behavior, this time from a Gitlab
> CI runner that is running as a service and trying to pipe output from
> Microsoft cl.exe while running configure.  This user reports that 3.3.4
> with your "[PATCH v2] Cygwin: pipe: Avoid deadlock for non-cygwin writer."
> applied to it does not solve the problem.
> 
> https://github.com/msys2/MSYS2-packages/issues/2893

I can confirm the sample script hangs indeed if the script is
running as SYSTEM account. However, in my test, the patch solves
the issue.

It would be very helpfull if a simple github repository with
github actions, which can reproduce the issue, is provided.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>