#11276: GHC hangs/takes an exponential amount of time with simple program -------------------------------------+------------------------------------- Reporter: mpickering | Owner: gkaracha Type: bug | Status: new Priority: highest | Milestone: Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by gkaracha): Replying to [ticket:11276 mpickering]:
This was discovered when trying to compile xml-conduit. Here is the standalone test case with a few comments indicating how to make it compile.
The program compiles with ghc-7.10.2 but fails with HEAD.
{{{#!hs -- Add this and it works -- dropWS :: Monad m => ConduitM Event o m (Maybe Event) }}}
Thanks for the comments! If you just add the signature it really does compile? This is a bit strange, since the check runs post-typechecking so I would expect to have the same signature inferred at this point so I would not expect it to make a difference. I'll have to take a closer look, thanks :) George -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11276#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler