I have been working on a Gentoo ebuild for Hat and ran across a few issues. First, it is the cabal package (not hat-package.conf) that needs to be piped to ghc-pgk register - to register the package (which is easy enough to work around). Futhermore, the file is somewhat incomplete. For example, if the import-dirs field is not added, then GHC is unable to find Hat's classes. Secondly, once I was able to get past that issue, the output from hat-trans fails to compile. Here is a sample of the output: ghc -package hat -o Insert Hat/Insert.o Hat/Insert.o: In function `r2iZ_info': : undefined reference to `HatziHat_mkModule_closure' Hat/Insert.o: In function `HatziInsert_asort_info': : undefined reference to `HatziHat_mkVariable_closure' Hat/Insert.o: In function `HatziInsert_ainsert_info': .... I am presuming that HatziInsert_ainsert_info, etc. are functions in libraries or headers that should be linked to the program, but, if so, where are they? Since I don't know, it has been hard to add this to the Cabal package or GHC's config files. The output was virtually the same for both programs I tried to run hat on. The first was Insert.hs, the example on the tutorial page and the second was a basic hello world: module Main where main = do putStrLn "Hello, world" Both programs appear to work 100% when run through GHC vanilla. If you could give me some insight into these errors, it would be greatly appreciated. Sincerely, Michael McDermott