#12906: GHC fails to typecheck Main module without main -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Well, you are right in that GHC //did// use to report more information—you just have to dig back a bit further: {{{ $ /opt/ghc/7.4.2/bin/ghc Bug.hs [1 of 1] Compiling Main ( Bug.hs, Bug.o ) Bug.hs:1:1: The function `main' is not defined in module `Main' Bug.hs:4:7: Couldn't match expected type `String' with actual type `IO ()' In the return type of a call of `print' In the expression: print (reverse s + 1) In an equation for `x': x s = print (reverse s + 1) ryanglscott at T450s-Linux64 in ~/Documents/Hacking/Haskell $ /opt/ghc/7.6.3/bin/ghc Bug.hs [1 of 1] Compiling Main ( Bug.hs, Bug.o ) Bug.hs:1:1: The function `main' is not defined in module `Main' }}} So this happened sometime between GHC 7.4 and 7.6. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12906#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler