#12060: GHC panic depending on what a Haskell module is named --------------------------------------+---------------------------------- Reporter: Darwin226 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.10.3 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: Runtime crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: --------------------------------------+---------------------------------- I'm trying to make bindings for the imgui C++ library and have encountered an apparent bug. I'm unable to produce a minimal example so I've packed up the whole project in a zip file. It only works on Windows for now but I assume this problem is platform dependant anyways. There's a module `UI.Imgui` that imports two things. A `FunPtr` wrapping function and an actual function defined in a .cpp file. Another module Main imports this module. If the project is run in a repl (in my case I'm doing `stack repl`) and then the `test` function is evaluated it results in a GHC panic {{{#!hs ghc.exe: panic! (the 'impossible' happened) (GHC version 7.10.3 for x86_64-unknown-mingw32): loadObj "C:\\Users\\Luka\\AppData\\Local\\Temp\\ghc5900_0\\ghc_5.o": failed Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug }}} Now here's the fun part. If you rename the module, file and it's import to something like Imgui2 it works. If you rename it to UI2.Imgui (with appropriate folder renaming) it also works! I'm sure a huge portion of the code is irrelevant. I couldn't reproduce this with simple .cpp files. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12060 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler