Cygwin test 3.5.0 tar symlinks error messages and failure status

[Daniel Abrahamsson <daniel.abrahamsson@prover.com>]

("Manually" replying to an email in the archive (https://cygwin.com/pipermail/cygwin/2023-May/253742.html) since I don't have the original email anymore).

Achim Gratz wrote:
> Brian Inglis via Cygwin writes:
> > Problem writing tar (with Cygwin default sys) symlinks before target
> > created under Cygwin 3.5.0 - error messages are issued and tar exits
> > with failure status!
> […]
> > The only likely culprit between 3.4.6 and that commit seems to be
> > commit 2023-04-18 fa84aa4dd2fb43eaf7fcdfb040aef854f2f19d01 Cygwin: fix
> > errno values set by readlinkat.
> >
> > Still seems to work as expected despite the error messages and failure status.
> >
> > Runs without any messages or failure under Cygwin stable 3.4.6.

We started seeing the same problem after cygwin 3.4.7 was released (I note it includes the commit Brian mentions). As a workaround, we just ignore the exit code of the tar command, but understandably we would rather not do that. Extracting the same archive works fine without warnings or errors on Linux.

> The interface mentioned above is known to be wonky on various systems.
> You might need to re-build tar in oder for it to detect any changed
> level of wonkiness and adapt accordingly.

Do you mean that the tar package would need an update?

// Daniel