design/build-system.md

@@ -2,7 +2,12 @@
 
 
 This page describes our current plan for making GHC's build system more
-malleable. 
+malleable. The new build system will be developed in a branch here:
+[ http://darcs.haskell.org/ghc-new-build-system/](http://darcs.haskell.org/ghc-new-build-system/)
+
+but if you want to grab it then you would probably prefer to start from a
+snapshot tarball:
+[ http://darcs.haskell.org/ghc-new-build-system-2008-11-20-ghc-corelibs-testsuite.tar.bz2](http://darcs.haskell.org/ghc-new-build-system-2008-11-20-ghc-corelibs-testsuite.tar.bz2)
 
 ## Design goals
 
@@ -286,6 +291,14 @@ libraries/%/ghc.mk: inplace/bin/ghc-cabal
 > >
 > > in the top-level Makefile.
 
+- There are two ways that we could handle the generation. We could
+  generate the complete rules, as above, but that makes them harder to
+  edit (as you'd actually have to edit some Haskell source that generates
+  them). Alternatively, we could generate them with a little `$(eval ...)`
+  in the makefile. the downside of that is that it requires make \>= 3.80,
+  which msys doesn't come with. However, it looks like it is easy to
+  upgrade an msys installation, so that's the route that we plan to take.
+
 - We don't want to require that the libraries ship part of the GHC build
   system in their tarballs, so instead we will generate the GNUmakefile's
   during ./configure.