Hi Ken, GhcHcOpts += -H24m -keep-hc-files-too -optc-DNO_REGS -optc-DUSE_MINIINTERPRETER -fno-asm-mangling -funregisterised -fvia-C GhcRtsHcOpts += -optc-DNO_REGS -optc-DUSE_MINIINTERPRETER -fno-asm-mangling -funregisterised -fvia-C SplitObjs = NO This isn't right: you shouldn't set GhcHcOpts in the first build. In the URL you gave, this line was commented out. That's certainly the reason for the core dumps. In GHC 5.00.2, there's an easier way. For the c1 & c2 builds, you can just set GhcUnregisterised = YES in build.mk, and you can set $long to empty. When you get around to bootstrapping on the Alpha, I'll probably need to help you some more, because bootstrapping from .hc files is quite tricky on 5.00. Cheers, Simon