Hi, I use ghc 6.4.1 on Mac OS X 10.4.5 and recently I have been getting some very strange errors. It has happened when I have been trying to compile DrIFT, and also today when I was compiling Haddock. The errors seem to change each time, and they always complain about an undefined symbol. For example, when compiling Haddock I got: /tmp/ghc24547.s:22969:Invalid mnemonic 'mtcts' /tmp/ghc24547.s:103127:Invalid mnemonic 'mtcur' /tmp/ghc24547.s:103430:Invalid mnemonic 'mtcur' /tmp/ghc24547.s:108482:Invalid mnemonic 'mtcts' I flushed out /tmp and ran make again, and this time I get: /tmp/ghc24804.s:unknown:Undefined local symbol L___DISCARE__$stub make[3]: *** [HsSyn.o] Error 1 make[2]: *** [all] Error 2 make[1]: *** [all] Error 1 make: *** [build] Error 1 Eventually Haddock will compile if I keep typing make every time ghc fails, but is there any reason why ghc is doing this? and how can I correct it? Thanks for your help. Chris Brown. Christopher Brown Ph.D. Student University of Kent. UK. http://www.cs.kent.ac.uk/people/rpg/cmb21/index.html