#15517: -O0 and pattern synonyms triggers panic in trimJoinCont -------------------------------------+------------------------------------- Reporter: sjakobi | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by monoidal): I reduced to: {{{ {-# LANGUAGE PatternSynonyms #-} module T15517 where data Nat = Z | S Nat pattern Zpat = Z class Family ki where sfrom :: Nat -> () -> ki instance Family Bool where sfrom Zpat = \_ -> False sfrom (S Z) = \_ -> False }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15517#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler