program exits at runtime with 'unimplemented/strange closure type' error
My program (attached) compiles fine, but at runtime exited with the following error message:
internal error: scavenge: unimplemented/strange closure type 12642 @ 0xd007e0
(GHC version 6.12.3 for i386_apple_darwin)
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug
Abort trap
It did this halfway through the set of parallel tasks between lines 150:154.
If it hadn't explicitly said to report this as a GHC bug, I would have assumed it was my mistake. As you can see from the program, I'm not hugely proficient at Haskell and in any case not primarily a programmer. Sorry if that makes it more difficult to trace.