#14489: GHC panic from emacs haskell mode -------------------------------------+------------------------------------- Reporter: ggoetz | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 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: -------------------------------------+------------------------------------- Hello, I encountered a ghc panic while going through one of the chapters from "Haskell Programming from first principles". The following error message is reported from flycheck checker from src/Main.hs in the attached files: {{{ Suspicious state from syntax checker haskell-stack-ghc: Flycheck checker haskell-stack-ghc returned non-zero exit code 1, but its output contained no errors: [1 of 2] Compiling Morse ( [some path]/haskell_programming/ch14/morse/src/Morse.hs, /var/folders/2s/c4mvtf0x5_b4d9gf18r65wwh0000gn/T/flycheck-haskell-ghc- cache90097PyL/Morse.o ) [2 of 2] Compiling Main ( /var/folders/2s/c4mvtf0x5_b4d9gf18r65wwh0000gn/T/flycheck90097c8R/Main.hs, /var/folders/2s/c4mvtf0x5_b4d9gf18r65wwh0000gn/T/flycheck-haskell-ghc- cache90097PyL/Main.o ) ghc: panic! (the 'impossible' happened) (GHC version 8.0.2 for x86_64-apple-darwin): initTc: unsolved constraints WC {wc_insol = [W] convertLine_a2Ml :: t_a2Mk[tau:1] (CHoleCan: convertLine)} Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Try installing a more recent version of haskell-stack-ghc, and please open a bug report if the issue persists in the latest release. Thanks! }}} Stack upgrade reports "Skipping binary upgrade, you are already running the most recent version". I'm not entirely sure whether this should be reported or not (I can't say I know what I'm doing...), so I'm reporting it just in case. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14489 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler