Re: [PATCH] global: resolve Perl executable via PATH

> On Wed, Apr 05, 2023 at 04:52:40PM +0200, Patrick Steinhardt wrote:
> 
> > > Is there a reason to not set PERL_PATH, which is the
> > > documented method to handle this?  From the Makefike:
> > > 
> > > # Define PERL_PATH to the path of your Perl binary (usually /usr/bin/perl).
> > 
> > Setting PERL_PATH helps with a subset of invocations where the Makefile
> > either executes Perl directly or where it writes the shebang itself. But
> > the majority of scripts I'm touching have `#!/usr/bin/perl` as shebang,
> > and that path is not adjusted by setting PERL_PATH.
> 
> Which scripts? If I do:
> 
>   mkdir /tmp/foo
>   ln -s /usr/bin/perl /tmp/foo/my-perl
>   make PERL_PATH=/tmp/foo/my-perl prefix=/tmp/foo install
> 
>   head -n 1 /tmp/foo/bin/git-cvsserver
> 
> Then I see:
> 
>   #!/tmp/foo/my-perl
> 
> And that is due to this segment in the Makefile:
> 
>   $(SCRIPT_PERL_GEN): % : %.perl GIT-PERL-DEFINES GIT-PERL-HEADER GIT-VERSION-FILE
>           $(QUIET_GEN) \
>           sed -e '1{' \
>               -e '        s|#!.*perl|#!$(PERL_PATH_SQ)|' \
>               -e '        r GIT-PERL-HEADER' \
>               -e '        G' \
>               -e '}' \
>               -e 's/@@GIT_VERSION@@/$(GIT_VERSION)/g' \
>               $< >$@+ && \
>           chmod +x $@+ && \
>           mv $@+ $@
> 
> And that behavior goes all the way back to bc6146d2abc ('build' scripts
> before installing., 2005-09-08). If there are some perl scripts we are
> "building" outside of this rule, then that is probably a bug.
> 
> The only thing I found via:
> 
>   find /tmp/foo -type | xargs grep /usr/bin/perl
> 
> was a sample hook (which is probably a bug; we do munge the hook scripts
> to replace @PERL_PATH@, etc, but I think the Makefile never learned that
> the template hook scripts might be something other than shell scripts).