#13394: PatternSynonyms/OverloadedStrings regression in GHC HEAD -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: highest | Milestone: 8.2.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: | PatternSynonyms Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Compile-time | Test Case: crash or panic | polykinds/T13394 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: closed => new * resolution: fixed => Comment: Thanks, Simon. But you didn't include the original program as the test case! Rather, you included a slightly tweaked program that doesn't have as many list elements in `TypeDataSymbol`. This is crucial, as the original program still fails with a GHC panic even after 8e053700f9357c1b9030c406130062795ae5015c: {{{ $ ~/Software/ghc2/inplace/bin/ghc-stage2 -O1 -fforce-recomp Bug.hs [1 of 1] Compiling Bug ( Bug.hs, Bug.o ) ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.1.20170307 for x86_64-unknown-linux): runtimeRepPrimRep typePrimRep (r_a28P :: TYPE rep_a28O) rep_a28O Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1191:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1195:37 in ghc:Outputable pprPanic, called at compiler/simplStg/RepType.hs:360:5 in ghc:RepType }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13394#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler