How to get an offline Haskell debug trace?

Question

In the Haskell docs here http://www.haskell.org/haskellwiki/Debugging it mentions Hat to do offline debug traces, but that page is online. I found it via Google but it seems outdated; what is the best way to do offline Haskell traces?

Answer 1

Hat isn't outdated -- olaf chitil revived it and is actively maintaining it: http://olafchitil.github.com/hat/

The latest version on hackage is tested to build with ghc 7.6.

It does, however, still only work on Haskell 98, with a few extensions. So programs that use more advanced GHC extensions (particularly regarding fancy type tricks) won't work with it. To my knowledge, there's nothing similar to hat that's been extended to handle a wider range of extensions to Haskell.