When building hat with ghc-5.04 I got the following error:
/usr/freebsdcvs/ports/devel/hat/work/hat-2.00/script/hat-trans -trusted -prelude PreludeTracing.hs
Fail: Cannot parse in .hx file PreludeBasic line (Var "seq",Value {args=-1, fixity=R, priority=0, letBound=True})
Curious. The field 'args' is lexically incorrect, it should be args=(-1) but my version of hat-trans (built with ghc-5.02.2) generates it correctly. In response to your report, I have just attempted to rebuild hat with ghc-5.04, and sure enough, it fails with the same error. Thus, it would appear that the program (hat-trans) compiled with 5.04 exhibits different behaviour from the same program compiled with 5.02.2. So I would guess that this is a bug in GHC, not in Hat. Regards, Malcolm