#15281: GHC 8.6.1 can't be bootstrapped with GHC 8.2.1 -------------------------------------+------------------------------------- Reporter: bgamari | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.6.1 Component: Compiler | Version: 8.4.3 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- 60e4bb4d305bc1a65457ee79b1e69c11b9ed747d (#9136) triggers a bug in GHC 8.2.1 which causes the build to fail with, {{{ ghc: panic! (the 'impossible' happened) (GHC version 8.2.1 for x86_64-unknown-linux): runtimeRepPrimRep typePrimRep (r_aqbE :: TYPE rep_aqbD) rep_aqbD Call stack: CallStack (from HasCallStack): prettyCurrentCallStack, called at compiler/utils/Outputable.hs:1133:58 in ghc:Outputable callStackDoc, called at compiler/utils/Outputable.hs:1137:37 in ghc:Outputable pprPanic, called at compiler/simplStg/RepType.hs:360:5 in ghc:RepType Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} This is a manifestation of #14393, which is fixed in 8.2.2 and later. We should probably add a `configure` check warning about this brokenness when the user tries to bootstrap with GHC 8.2.1. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15281 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler