lang/perl5 needs MAKE_JOBS_SAFE=no

[Francis GUDIN <francis.lists.pkgsrc-users%fug-fr.org@localhost>]

Hi,

There's a race during perl's building process: see

http://www.gossamer-threads.com/lists/perl/porters/259782
(just been hit by the issue)

Should I send-pr for that ? And what's the best place to add 
MAKE_JOBS_SAFE=no, Makefile or Makefile.common ?

Thanks in advance,
--
Francis