#13889: GHC 8.0.2 panics when trying a simple snippet involving Parsec -------------------------------------+------------------------------------- Reporter: timmyjose | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: duplicate | Keywords: parsec, | ghc8.0.2, macOS Sierra Operating System: MacOS X | Architecture: x86_64 Type of failure: Compile-time | (amd64) crash or panic | Test Case: Blocked By: | Blocking: Related Tickets: #13106 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => closed * resolution: => duplicate * related: => #13106 Comment: Thanks for the bug report. This is a duplicate of #13106, which has been fixed in GHC 8.2.1. In 8.2.1, I get a reasonable error message: {{{ $ /opt/ghc/8.2.1/bin/ghc Bug.hs [1 of 1] Compiling Main ( Bug.hs, Bug.o ) Bug.hs:1:1: error: The IO action ‘main’ is not defined in module ‘Main’ | 1 | import Text.ParserCombinators.Parsec hiding (spaces) | ^ Bug.hs:4:10: error: Variable not in scope: anyOf :: [Char] -> Parser Char | 4 | symbol = anyOf "!$%&|*+-/:<=?>@^_^~#" | ^^^^^ }}} Alternatively, you can make the panic go away in 8.0.2 by just adding `module SimpleParser where` at the top of the file (the lack of `main` is confusing GHC in 8.0.2). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13889#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler