[Haskell-cafe] building a patched ghc

[braver]

How do I get the latest 6.12 source and cherry-pick selected patches
from the trunk, e.g. Simon's GC fixes?  The wiki says that you get the
head with

darcs get --lazy http://darcs.haskell.org/ghc

and the 6.12 with

darcs get --lazy http://darcs.haskell.org/ghc-6.12/ghc

Since the trunk is big enough, I wonder if 6.12 a subset of it and can
be obtained from it?  The tags are not informative.  If I get the
branch, how will I be able to get the patches from the head, once
they're separate repos?

-- Alexy