#11748: GHC runtime linker: fatal error: I found a duplicate definition for symbol -------------------------------------+------------------------------------- Reporter: jeiea | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template Haskell | Version: 7.10.3 Resolution: | Keywords: Operating System: Windows | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: #11223 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): In the second reproducer, `child1`'s module `Lib` calls `rgb`, which is supposed to be defined by `child1`'s `HsGDI.c`. But the library `child1` does not have `c-sources: src/HsGDI.c`, only the (irrelevant) `child1-exe` does. It happens that `ghc-bug-maybe-exe` links indirectly against `Win32` (via `inline-c`), which coincidentally would provide a symbol `rgb`, but because there is no dependency of `child1` on `Win32`, it happened that `Win32` was given before `child1` on the linker command line and so the linker didn't know that there would be a reference to `rgb` when it processed `Win32`. The right thing to do of course is to specify `c-sources: src/HsGDI.c` in the `child1` ''library'' section; then you might get a duplicate symbol error again, because you chose the same name as `Win32` did. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11748#comment:16 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler