#13803: Panic while forcing the thunk for TyThing IsFile (regression) -------------------------------------+------------------------------------- Reporter: inaki | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 8.2.1 Component: Compiler | Version: 8.2.1-rc2 Resolution: fixed | Keywords: hs-boot 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): Phab:D3742 Wiki Page: | -------------------------------------+------------------------------------- Comment (by inaki): Thanks for the fix, I just gave it a try. Unfortunately the original issue still seems to be present (perhaps I am hitting #13981?). The error message I am getting is basically the same as before: {{{ <no location info>: error: ghc-stage2: panic! (the 'impossible' happened) (GHC version 8.2.0.20170720 for x86_64-unknown-linux): tcIfaceGlobal (local): not found You are in a maze of twisty little passages, all alike. While forcing the thunk for TyThing IsFile which was lazily initialized by initIfaceCheck typecheckLoop, I tried to tie the knot, but I couldn't find IsFile in the current type environment. If you are developing GHC, please read Note [Tying the knot] and Note [Type-checking inside the knot]. Consider rebuilding GHC with profiling for a better stack trace. Contents of current type environment: [] 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/iface/TcIface.hs:1696:23 in ghc:TcIface Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} This is when trying to compile `gi-gio`, following the same steps as in the original report, but using GHC 8.2 from git. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13803#comment:20 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler