#11197: Overeager deferred type errors -------------------------------------+------------------------------------- Reporter: goldfire | Owner: goldfire Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 7.11 checker) | Resolution: | Keywords: TypeInType 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 sighingnow): When `-fdefer-type-errors` is enabled, the program {{{#!hs main = do putStrLn "Hi there." putStrLn 1 }}} works well. However the program {{{#!hs main = do putStrLn "Hi there." putStrLn True }}} emits the deferred type error message eagerly and doesn't execute `putStrLn "Hi there."`. In the first case, the type error is `EvVarDest evar`: {{{ Wanted = WC {wc_simple = [WD] $dNum_a1zB {0}:: Num String (CDictCan(psc))} }}} However in the second case, the type error is `HoleDest hole`: {{{ Wanted = WC {wc_simple = [WD] hole{co_a1zO} {0}:: (Bool :: *) GHC.Prim.~# ([Char] :: *)} }}} Seems that the coercion hole is placed at wrong place. This ticket may related to Trac #14584. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11197#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler