CMake reports GCC is broken. Where do I start?

Question

I am trying to compile a project, but CMake stops right at the beginning with the message that gcc is broken (see below). I am ignoramus when it comes to CMake, so any help where to get me starting debugging this problem is very very welcome.

• GCC (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3 (I checked that my GCC compiles a 'hello world' problem)
• CMake version 2.8.7
• CMake command: cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug ../Mantid

Output to terminal:

-- The C compiler identification is GNU
-- The CXX compiler identification is GNU
-- Could not determine Eclipse version, assuming at least 3.6 (Helios). Adjust CMAKE_ECLIPSE_VERSION if this is wrong.
-- Check for working C compiler: /usr/bin/gcc-4.6
-- Check for working C compiler: /usr/bin/gcc-4.6 -- broken
CMake Error at /usr/share/cmake-2.8/Modules/CMakeTestCCompiler.cmake:52 (MESSAGE):
The C compiler "/usr/bin/gcc-4.6" is not able to compile a simple testprogram.

It fails with the following output:

Change Dir: /home/jmborr/devel/mantidproject/mantid/Code/debug/CMakeFiles/CMakeTmp

Run Build Command:/usr/bin/make "cmTryCompileExec/fast"

/usr/bin/make -f CMakeFiles/cmTryCompileExec.dir/build.make CMakeFiles/cmTryCompileExec.dir/build

make[1]: Entering directory `/home/jmborr/devel/mantidproject/mantid/Code/debug/CMakeFiles/CMakeTmp'

/usr/bin/cmake -E cmake_progress_report /home/jmborr/devel/mantidproject/mantid/Code/debug/CMakeFiles/CMakeTmp/CMakeFiles 1

Building C object CMakeFiles/cmTryCompileExec.dir/testCCompiler.c.o

/usr/bin/gcc-4.6 /usr/include -o CMakeFiles/cmTryCompileExec.dir/testCCompiler.c.o -c /home/jmborr/devel/mantidproject/mantid/Code/debug/CMakeFiles/CMakeTmp/testCCompiler.c

gcc-4.6: warning: /usr/include: linker input file unused because linking not done

Linking C executable cmTryCompileExec

/usr/bin/cmake -E cmake_link_script CMakeFiles/cmTryCompileExec.dir/link.txt --verbose=1

/usr/bin/gcc-4.6 /usr/include /usr/lib CMakeFiles/cmTryCompileExec.dir/testCCompiler.c.o -o cmTryCompileExec -rdynamic

/usr/bin/ld: cannot find /usr/include: File format not recognized

/usr/bin/ld: cannot find /usr/lib: File format not recognized

collect2: ld returned 1 exit status

make[1]: Leaving directory

Answer 1

Check this link.

I had the same problem. I think the problem is that you need more parameters to compile (like linker-script, flags ...). Change your CMakeLists.txt like this and try it again:

INCLUDE(CMakeForceCompiler)
CMAKE_FORCE_C_COMPILER(gcc GNU)
CMAKE_FORCE_CXX_COMPILER(g++ GNU)

Do not forget to set the path to the compiler in your environment variables.