[Haskell-cafe] Compiling Setup.hs with -threaded

[Michael Orlitzky]

I found a weird bug at,

  https://bugs.gentoo.org/show_bug.cgi?id=537500

There is an awesome tool called shellcheck:

  git clone https://github.com/koalaman/shellcheck.git

and we want to run its test suite. Basically:

  * If you run the test suite using runghc, then it works fine.
  * If you compile Setup.hs to setup, then the test suite hangs.
  * But if you compile Setup.hs to setup using -threaded, it works?

Normally I would blabber on about what I think the problem could be, but
the WTF factor here is just too high. Should we (always?) be compiling
Setup.hs with -threaded? Or is this a bug in the runtime or a library or
REALITY ITSELF?