Per my prior message to tech-pkg which hit a resounding silence of
objections, I will be making the following changes today to help us whip the
tree into more portable shape:

* USE_BUILDLINK3=YES will be unconditional.  (In fact, USE_BUILDLINK3 will
  be ignored altogether by mk/; but see below.)

* NO_BUILDLINK and NO_WRAPPER will be ignored by mk/.  If a build happens,
  these phases will happen.

* The existing NO_BUILD will imply the previous NO_BUILDLINK and NO_WRAPPER.
  If no build happens, those phases are not needed.

* NO_TOOLS will be ignored by mk/.  The tools phase, which provides much
  more than just the C compiler, will always happen regardless of package.
  This will make metapackage builds only slightly slower, in trade for far
  less user error.

===

NOTES:

This *will* break some builds, but justifiably so.  Builds which break by
this change are missing bl3 includes or are still using classical DEPENDS
lines -- and thus are likely not correctly depending on packages they
actually need.  When fixing this breakage, please make sure to bump
PKGREVISION, as addition of bl3 files does change the contents of DEPENDS
for that package.

I will not be removing all the USE_BUILDLINK3=YES, NO_TOOLS, NO_BUILDLINK,
or NO_WRAPPER lines yet, as I don't want to diverge greatly from 2005Q1.
Rather, I will remove these lines shortly before 2005Q2 is branched.  At
that same time, I'll remove autogeneration of USE_BUILDLINK3 from url2pkg.

If a build is needed but a C compiler is *not* needed, the tools and wrapper
phases can be shortened by setting USE_LANGUAGES to empty.  (This is the
proper way to do it already, but is not yet widely used.)

-- 
-- Todd Vierling <tv@duh.org> <tv@pobox.com>