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I am having multi-version of GCC in ubuntu, gcc-4.8 and gcc-5. Using gcc -v will gives gcc version 4.8.4, so looks like the default is 4.8, but I need to use the gcc-5.

I tried How to specify new GCC path for CMake: 

export CC=/usr/bin/gcc-5
export CXX=/usr/bin/g++-5
// find the path by using 'which gcc-5'

and specific:

-DCMAKE_C_COMPILER=/usr/bin/gcc-5 
-DCMAKE_CXX_COMPILER=/usr/bin/g++-5

but gives an error:

ubuntu@skc:~/jumanpp-2.0.0-rc2/bld$ cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=~/Jumanpp -DCMAKE_C_COMPILER=/usr/bin/gcc-5 -DCMAKE_CXX_COMPILER=/usr/bin/g++-5
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
-- Check for working C compiler: /usr/bin/gcc-5
-- Check for working C compiler: /usr/bin/gcc-5 -- broken
CMake Error at /usr/share/cmake-3.2/Modules/CMakeTestCCompiler.cmake:61 (message):
  The C compiler "/usr/bin/gcc-5" is not able to compile a simple test
  program.
JustWe
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1 Answers1

1

solved it by changing the default GCC: 

sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-6 60 --slave /usr/bin/g++ g++ /usr/bin/g++-6

(I need higher version, so change from 4.8 to 6)

JustWe
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