After installing some libghc-*-dev packages so cabal didn't have to pull them down, it worked.
Since I am planning to learn Haskell using Snap for some skunk work, I wanted to make sure it worked at work as well, so I logged into a machine running Ubuntu 10.04 (lucid lynx) and tried there.
No luck, got an error message. Hm. Not being knowledgable in GHC, Haskell nor Snap, I turned to the IRC-channel listed in the website.
After reporting my problem, a fix was committed literally within seconds. A new release was done and uploaded within minutes, and within half an hour I could test the fix and report success back!
That is quite impressive.
I thanked and threatened to be back with stupid questions.
Now I just have to learn the language and the framework, and actually get something done...