Hi, After downgrading a mingw gcc from 3.3.1 to 3.2.3 I've managed to build and install ghc 6.3 compiler. Unfortunately, it cannot compile source files. It seems it incorrectly invokes gcc . "ghc -c -v filt.hs" gives something like this: ghc-6.3 (incorrect): ................... *** Assembler g:\Progs\ghc-6.3\gcc -B"g:\Progs\ghc-6.3\gcc-lib/" -I. -I. -c C:\DOCUME~1\Awson\LOCALS~1\Temp\ghc1252.s -o .\Main.o Failed: g:\Progs\ghc-6.3\gcc -B"g:\Progs\ghc-6.3\gcc-lib/" -I. -I. -c C:\DOCUME~1\Awson\LOCALS~1\Temp\ghc1252.s -o .\Main.orawSystem: does not exist (No such file or directory) ................... ghc-6.0.1 (correct): ................... *** Assembler G:\Progs\ghc-6.0.1\gcc -B"G:\Progs\ghc-6.0.1\gcc-lib/" "-I." "-I." "-c" "C:\DOCUME~1\Awson\LOCALS~1\Temp\ghc812.s" "-o" "filt.o" ................... Meanwhile, ghc-6.3 correctly outputs intermediate .c or .s (when compiling without gcc) files. I'm completely stuck. Regards, Kyra