plague 0.4

[Dan Williams]

Hi,

So 0.4/HEAD has built about 500 packages so far without huge problems on
my Sparc cluster.  Dennis has been building Fedora Extras for Sparc for
a while with 0.4/HEAD as well.  I think it's pretty solid right now, so
the time has come to think about updating the Extras buildsystem to 0.4.

One of the larger improvements has been the ability to use real
databases, like Postgres, as the job database rather than SQLite.  We've
all seen the issues with SQLite, which doesn't play very well in a
multithreaded situation.  Some of that can painfully fixed, but the fact
remains that SQLite just doesn't have the features that we really want
out of it (ie, row locking).  SQLite can still be used in a smaller
buildsystem though, where it works just fine and doesn't require any
setup.

Seth: Jeremy thought you'd be quite averse to using Postgres...  Not
sure what your feelings here really are.  I've noticed quite a big
improvement by switching to Postgres when rebuilding an entire distro,
namely in the buildsystem not falling over due to database contention.

If there's not much else to fix up, I'll push out a plague 0.4 release
this week and we can work on migrating the current Extras boxes to it.

Dan