[Haskell-cafe] Getting the 'ThreadId' of the calling thread

(I'm trying to update a package that was written with GHC 6.10.4 in mind.) I feel that a 'myThreadId' action, which is defined in this module [1], is useless, but I'm not sure. I think it will always return the "Map.find: element not in the map" exception because a 'threadMap' contains an empty 'ThreadMap'. Is it right, or am I missing something? [1] https://gitweb.torproject.org/tordnsel.git/blob/HEAD:/src/TorDNSEL/Control/C...