#12761: Type aliases for TypeError constrains fire during compilation time -------------------------------------+------------------------------------- Reporter: danilo2 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: GHC rejects Unknown/Multiple | valid program Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Hello! The following code should compile fine: {{{ module Main where import GHC.TypeLits (ErrorMessage(Text, ShowType, (:<>:)), TypeError) type MyError a b = TypeError (ShowType a :<>: ShowType b) main :: IO () main = return () }}} but it raises an error during compilation: {{{ Main.hs:5:1: error: • ab • In the type synonym declaration for ‘MyError’ }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12761 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler