Re: [PATCH] CI: Add a CPAN cache on Windows

On Fri, Jun 5, 2026 at 11:38 AM Andres Freund <andres(at)anarazel(dot)de> wrote:
> In 93d97349461347d952e8cebdf62f5aa84b4bd20a, I kinda had implemented such
> caching for macos. There I used
> PERL5LIB: ${HOME}/perl5/lib/perl5
>
> to put the cache somewhere under our control. Any reason to not do that?

As a Perl novice, I was worried about setting that. The Windows
runners have multiple installations of Perl and I don't want them to
ever collide (similar to my PYTHONHOME concern in the other thread).
Is that a reasonable fear?

> > - - name: Install dependencies
> > + # Rebuild the CPAN cache whenever `perl -V` changes.
> > + - name: Compute Perl version cache key
> > + id: perlkey
> > + shell: 'C:\msys64\usr\bin\bash.exe --login -eo pipefail "{0}"'
> > + run: |
> > + perl_hash=$(/c/Strawberry/perl/bin/perl -V | md5sum | cut -f1 -d ' ')
> > + echo "key=perl${perl_hash}" >> "$GITHUB_OUTPUT"
>
> Hm. It'd be nicer if we didn't have to repeat this part between the two
> tasks... Perhaps we can make it work using the small overlap between the
> different shells?
>
> Or maybe shell: bash would actually work well enough between the tasks (without
> -- login it might not overwrite PATH).

I'll see if I can make something work.

Thanks!
--Jacob