|Version 1 (modified by simonmar, 5 years ago) (diff)|
Debugging the compiler
At compile time (see also the relevant User Manual section):
- Use -v3 or -v4 to get an idea about what GHC is doing when the problem occurs.
- Add -dcore-lint the GHC command line when compiling each Haskell module. This makes GHC type-check the intermediate program after every optimisation pass, which often nails a fault.
- Add -ddump-simpl to see the optimised Core output. There are a number of other -ddump-x flags; see the user manual.
- The flag -dppr-debug makes the -ddump-x flags print much more verbose output. Use this if you are getting desperate!