I'm having problems building GHC 6.0 with GCC 3.3. I've fixed a couple of problems with comments in CPP macros as seen elsewhere, and then everything seemed to be going fine until it came to create stage2/ghc-6.0 and it failed with a huge number of things like

stage2/utils/Util.o(.text+0xb8): In function `r4c8_entry': : undefined reference to `GHCziBase_True_closure' stage2/utils/Util.o(.text+0xc8): In function `r4c8_entry': : undefined reference to `GHCziBase_False_closure'

Fixed in CVS, thanks for the report. Workaround: don't use GCC 3.3 (yet). Cheers, Simon