#14356: "Main: thread blocked indefinitely in an MVar operation" in fixIO -------------------------------------+------------------------------------- Reporter: nickkuk | Owner: (none) Type: bug | Status: new Priority: low | Milestone: Component: Runtime System | Version: 8.2.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Poor/confusing | Unknown/Multiple error message | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by dfeuer): * priority: normal => low * failure: Incorrect result at runtime => Poor/confusing error message Comment: nickkuk, as alexbiehl sort of suggests, this is the expected behavior for the second example, although I think it would be worth trying to improve the error message. Unfortunately, your `mdo` example was stripped down too far to be able to interpret. Do you think you can provide a proper reproduction of what you see as bad `mdo` desugaring? I'll mark this low priority for the error message improvement; if you find a real desugaring problem we'll bump it back up. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14356#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler