Osrm-backend: CMake complains about GCC version but newer is installed

[retorquere]

When running cmake, I'm getting

-- Enabling mason
-- The C compiler identification is GNU 4.8.5
-- The CXX compiler identification is GNU 4.8.5
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Error at cmake/JSONParser.cmake:287 (string):
  string end index: 1 is out of range -1 - 0
Call Stack (most recent call first):
  cmake/JSONParser.cmake:232 (_sbeMoveToNextNonEmptyCharacter)
  cmake/JSONParser.cmake:71 (_sbeParseObject)
  cmake/JSONParser.cmake:22 (_sbeParse)
  CMakeLists.txt:64 (sbeParseJson)


-- Building on a 64 bit system
CMake Error at CMakeLists.txt:120 (message):
  GCC>=5.0 required.  In case you are on Ubuntu upgrade via
  ppa:ubuntu-toolchain-r/test


-- Configuring incomplete, errors occurred!
See also "/scistor/guest/ehs215/osrm-backend/build/CMakeFiles/CMakeOutput.log".
make: *** No targets specified and no makefile found.  Stop.

but gcc --version reports gcc (GCC) 6.3.0

gcc 4.8.5 is also installed on this system, but the first gcc in my path is 6.3.0.

[TheMarex]

@retorquere can you print what g++ --version shows? Might be the path for the C++ compiler is not setup correctly.

[retorquere]

$ g++ --version
g++ (GCC) 6.3.0
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

$ /usr/bin/g++ --version
g++ (GCC) 4.8.5 20150623 (Red Hat 4.8.5-16)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[TheMarex]

might be it ignores the path for some reason. rm CMakeCache.txt && CXX=g++-6 CC=gcc-6 cmake .. should work.

[retorquere]

That doesn't work either (I don't have those names in my path), but this got me past the current problem:

export CC=`which gcc`
export CXX=`which g++`

[pratikone]

CXX=g++-6 CC=gcc-6 cmake worked for me