[enhancement] proposal - make all ports independent of which version of Perl is installed or the major one

[Eric Hall]

On Wed, May 16, 2012 at 03:44:08AM +0200, Clemens Lang wrote:
> On Tue, May 15, 2012 at 06:05:45PM -0700, Bradley Giesbrecht wrote:
> > I do not recall why but at some point I needed "perl5.12 +threads
> > +shared" and after upgrading  perl5.12 with these variants NONE of my
> > perl modules were found.  It was required that I reinstall all perl
> > modules.
> > 
> > Would perl modules built with perl -threads -shared work after
> > switching to perl +threads +shared?
> 
> No, they probably would not, as rev-upgrade goes ahead and starts
> rebuilding all your perl modules as soon as you do that. However,
> rev-upgrade happily automates this process, so it's not that bad.
> 
> > Is there a reason that perl does not build +threads +shared always or
> > as default?
> 
> This question has been asked a couple of times on this list now and I
> have yet to hear a reason for why our perl isn't always +threads and
> +shared other than "I think I once knew somebody who back in the old
> days had some unspecified specified problem with perl +threads/+shared."
> ;)
> I'll leave the decision to the maintainer, but I think it's time to go
> for a full-featured perl and fix any problems (if any) that might arise
> in the modules.
> 

	Both +thread and +shared will impose a performance penalty as
of perl5.12 (see this thread: 
http://www.nntp.perl.org/group/perl.perl5.porters/2009/11/msg153361.html).
I don't know if this is still true for perl5.14 or not (I didn't find
anything doing a quick search).
	Can someone re-iterate the reasons for using +shared and/or +threads?



		-eric