#9010: TemplateHaskell leads to an "unknown symbol" error -------------------------------------+------------------------------------- Reporter: Feuerbach | Owner: Type: bug | Status: infoneeded Priority: high | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by rwbarton): Well I'm a bit stuck being unable to reproduce the behavior you seem to be getting. Here's what I think is going on: 1. Somehow, I don't know how, you're getting GHC's runtime linker involved. I guess this must be due to some difference in configuration of opencv, but I don't understand how. 2. From `man nm`: {{{ "u" The symbol is a unique global symbol. This is a GNU extension to the standard set of ELF symbol bindings. For such a symbol the dynamic linker will make sure that in the entire process there is just one symbol with this name and type in use. }}} GHC's runtime dynamic linker presumably doesn't understand this symbol type since it is a non-standard extension. And that's probably what causes it to report the symbol as not found. Fixing 2 would require changes to GHC, so it probably makes sense to fix 1. But I don't know why you are in this situation. Perhaps build output with `cabal -v` and `ghc -v` would help. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9010#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler