#13461: Panic on compile of file with a hole and nothing else -------------------------------------+------------------------------------- Reporter: Tritlo | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.2 checker) | Resolution: | Keywords: Operating System: MacOS X | Architecture: x86_64 | (amd64) Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by Tritlo: Old description:
The example is very simple, just:
{{{ test :: Int -> Int test = _ }}}
which produces the panic:
{{{ [1 of 1] Compiling Main ( manyIdsTest.hs, manyIdsTest.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-apple-darwin): initTc: unsolved constraints WC {wc_insol = [W] __awc :: t_awb[tau:1] (CHoleCan: _)} }}}
I suspect that there might be a missing case when there is nothing else in scope.
New description: The example is very simple, just: {{{ test :: Int -> Int test = _ }}} which produces the panic: {{{ [1 of 1] Compiling Main ( manyIdsTest.hs, manyIdsTest.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-apple-darwin): initTc: unsolved constraints WC {wc_insol = [W] __awc :: t_awb[tau:1] (CHoleCan: _)} }}} I suspect that there might be a missing case when there is nothing else in scope, since {{{ test :: Int -> Int test = _ main :: IO () main = return () }}} compiles just fine (i.e. with no panic, but still reports the typed hole. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13461#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler