bug#74453: running make failed when perl is installed in the very long path

Collin Funk cited me:
> As Bruno Haible said in a Gnulib thread [1]:
> 
> > "#!/usr/bin/env perl" does not work on GuixSD (where the only program
> > that has a hardcoded file name is /bin/sh; there is no /usr and no
> > /bin/env on this distro).
> 
> So I don't think it would work in this case.
> 
> Collin
> 
> [1] https://lists.gnu.org/archive/html/bug-gnulib/2019-06/msg00022.html

That was in 2019. Meanwhile, in GuixSD 1.4, both /bin/sh and /usr/bin/env
exist. So, writing

  #!/usr/bin/env perl

is now again the portable way to start a perl script.

Bruno