#15436: Compile-time panic, Prelude.!!: negative index -------------------------------------+------------------------------------- Reporter: pbrisbin | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.5 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: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * cc: simonpj (added) Comment: This was probably caused by commit 193664d42dbceadaa1e4689dfa17ff1cf5a405a0 (`Re-engineer caseRules to add tagToEnum/dataToTag`), considering that this panic does not occur on GHC 8.2 or earlier (see also #14680). simonpj, do you know what is happening here? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15436#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler