[Fedora-packaging] Fwd: When to use perl(:WITH_...) requires?

[Chris Weyl]

Ok, maybe the third list is the charm :)

Could someone please explain to me -- or point me at a doc somewhere
-- what these provides are (I gather they indicate features perl was
built with), and, more importantly, when they should be used in a
spec?  They seem as if they may be fairly important, but there's
nothing indicating when they should be used, if they're relevant to
noarch packages, etc etc, and neither the wiki nor google (oddly
enough) is shedding any light on it...

             -Chris

---------- Forwarded message ----------
From: Chris Weyl <cweyl at alumni.drew.edu>
Date: Jul 31, 2006 8:15 AM
Subject: When to use perl(:WITH_...) requires?
To: Discussion related to Fedora Extras <fedora-extras-list at redhat.com>


Hey all --

Perl provides a number of provides flags, e.g.:

perl(:WITH_ITHREADS)
perl(:WITH_LARGEFILES)
perl(:WITH_PERLIO)
perl(:WITH_THREADS)

Most perl module spec files only deal with perl(:MODULE_COMPAT_5.8.8),
etc.  But I see a number of them (arch-specific, typically), do use
these flags, along the lines of:

Requires: %(perl -MConfig -le 'if (defined $Config{useithreads}) {
print "perl(:WITH_ITHREADS)" } else { print "perl(:WITHOUT_ITHREADS)"
}')

etc, etc.

So, when should a packager use these?  Should lines along the one
above be included for all flags in an arch-specific spec file?  What's
a good rule of thumb here?  (And, are these flags documented anywhere?
 A cursory search of the wiki isn't turning up anything for me.)

                       -Chris

--
Chris Weyl
Ex astris, scientia