#12595: Linker failure: multiple definition of -------------------------------------+------------------------------------- Reporter: | Owner: MikolajKonarski | Type: bug | Status: new Priority: high | Milestone: 8.0.2 Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Linux Architecture: x86_64 | Type of failure: GHC rejects (amd64) | valid program Test Case: | Blocked By: Blocking: | Related Tickets: #10531 Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Linker fails on a normal project built with cabal (-O1), both on my home machine (GNU gold (GNU Binutils for Ubuntu 2.22) 1.11) and on travis with GHC 8.0.1: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457149#L589 and with head: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457156#L602 It compiles fine with -O0 (but if fails with -O2): https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457144 with older GHCs: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159457155 and after the symbol the linker complains about is removed: https://travis-ci.org/LambdaHack/LambdaHack/jobs/159506870 As seen on travis, the way to reproduce it is just cabal install of https://github.com/LambdaHack/LambdaHack/commit/0d2bbd6eadca7a10292ab67ab1fa... which also shows the offending line. I took the liberty of adding it to 8.0.2 milestone, because if it affects all x86_64 machines, it's pretty serious. Please feel free to downgrade. If the bug is confirmed, I can attempt creating a small reproducing case, but it would require gtk, so it would compile forever anyway. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12595 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler