#8490: OS X 10.9 gcc-4.8 unknown symbol `__objc_empty_table` ----------------------------------+--------------------------------------- Reporter: jloos | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: Compile-time crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+--------------------------------------- I'm not sure if and how far the ghc-7.6.3 support for OS X is planned, but I hit a (possible) linker error with 7.6.3. I installed a homebrew gcc-4.8 and changed the ghc config to use it. I tried to compile the [http://hackage.haskell.org/package/bindings-GLFW bindings-GLFW] package, which was successful, and run `cabal test` on it, which fails with following error: {{{ final link ... ghc: lookupSymbol failed in relocateSection (relocate external) dist/build/HSbindings-GLFW-3.0.3.o: unknown symbol `__objc_empty_vtable' linking extra libraries/objects failed }}} After some research I discovered that this symbol (surely just the first which fails) is part of the Objective-C Runtime. The /usr/lib/libobjc.dylib exports this symbol. In desperation I think I nearly reached the google quota with my research, further steps I tried: Explicitly link the libobjc lib {{{ ghci -lobjc dist/build/HSbindings-GLFW-3.0.3.o -framework Foundation -framework Cocoa -framework IOKit }}} With the same result as above: {{{ GHCi, version 7.6.3: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading object (static) dist/build/HSbindings-GLFW-3.0.3.o ... done Loading object (dynamic) /usr/lib/libobjc.dylib ... done Loading object (framework) IOKit ... done Loading object (framework) Cocoa ... done Loading object (framework) Foundation ... done final link ... ghc: lookupSymbol failed in relocateSection (relocate external) dist/build/HSbindings-GLFW-3.0.3.o: unknown symbol `__objc_empty_vtable' linking extra libraries/objects failed }}} I found a [https://github.com/mxcl/homebrew/issues/23687 homebrew issue] related to gcc and the Apple switch from libstdc++to libc++ in 10.9 and i tried to force linking with explicit `-stdlib=libstdc++` in the cabal file (ld-options). But i guess this issue isn't related to the `__objc_***` problem, just tried it in desperation. Last week I managed to build ghc HEAD with clang bootstrapped with 7.4.6: the new linker mechanic seems to resolves this problem in a way (sadly some other packages aren't jet compatible with 7.8) So I'm not sure if this report is okay, if not, pardon me :) I'm aware of the problems with the current ghc-7.6.3 and the the changes OS X 10.9 brings with it (according to reddit/haskell cafe). The current suggestions is to not use the XCode-5.0.1/clang together with ghc-7.6.3. So I tried gcc from homebrew. I know that 7.8 will bring better linker capabilities, maybe there are just some flags to fix this specific problem with 7.6.3...? I didn't find it. So I thought it's better to report it. If further informations are required, I will try to provide them as fast as possible but I will have to downgrade to 10.8 tomorrow around 6 a.m. UTC. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8490 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler