#648: Cabal incorrectly reports missing C library IL ----------------------------+----------------------------------------------- Reporter: GregoryWeber | Owner: Type: defect | Status: new Priority: normal | Milestone: Component: Cabal library | Version: 1.6.0.1 Severity: normal | Keywords: Difficulty: unknown | Ghcversion: Platform: Linux | ----------------------------+----------------------------------------------- This problem occurs with Cabal version 1.8.0.2 on Arch Linux (this version number does not appear in the Version selector, so I have left it at 1.6.0.1) and ghc version 6.12.1. Trying to install Codec-Image-DevIL, either version 0.1 or 0.2.0, 'runghc Setup configure' produces a misleading error message: $ runghc Setup configure Configuring Codec-Image-DevIL-0.2.0... Setup: Missing dependency on a foreign library: * Missing C library: IL This problem can usually be solved by installing the system package that provides this library (you may need the "-dev" version). If the library is already installed but in a non-standard location then you can use the flags --extra-include-dirs= and --extra-lib-dirs= to specify where it is. The error message "Missing C library: IL" is incorrect: the Arch 'devil' package is installed, and the include and library files are present in the normal locations: $ pacman -Q devil devil 1.7.8-6 $ ls /usr/include/IL devil_cpp_wrapper.hpp il.h ilu.h ilu_region.h ilut.h $ ls /usr/lib/*IL* /usr/lib/libIL.a /usr/lib/libILU.a /usr/lib/libILUT.a /usr/lib/libIL.so@ /usr/lib/libILU.so@ /usr/lib/libILUT.so@ /usr/lib/libIL.so.1@ /usr/lib/libILU.so.1@ /usr/lib/libILUT.so.1@ /usr/lib/libIL.so.1.1.0* /usr/lib/libILU.so.1.1.0* /usr/lib/libILUT.so.1.1.0* There does seem to be an error in Codec-Image-DevIL.cabal: where it says Extra-Libraries: IL it should say any of the following (take your choice, all of them work): Extra-Libraries: IL, pthread Extra-Libraries: IL, rt Extra-Libraries: IL, pthread, rt It seems that using the IL library in a C program requires linking with -lrt or -pthread in addition to -lIL. I have the impression that in the configuration step, when Cabal sees the line Extra-Libraries: IL it writes a small C program that tries to include that library, and reports the library is missing if there's an error in compiling and linking the C program. Maybe Cabal needs to interpret the C compiler's and linker's error messages more carefully. -- Ticket URL: http://hackage.haskell.org/trac/hackage/ticket/648 Hackage http://haskell.org/cabal/ Hackage: Cabal and related projects