CMAKE_C_COMPILER is not a full path to an existing compiler tool

Question

I recently explored distcc and couldn't make it work. So I

sudo apt-get remove distcc

After that, I get the error

==> Processing catkin package: 'gencpp'
==> Building with env: '/opt/ros/kinetic/env.sh'
Makefile exists, skipping explicit cmake invocation...
==> make cmake_check_build_system in '/home/pi/ros_catkin_ws/build_isolated/gencpp'
-- The C compiler identification is unknown
-- The CXX compiler identification is unknown
CMake Error at CMakeLists.txt:2 (project):
  The CMAKE_C_COMPILER:

    /usr/local/bin/cc

is not a full path to an existing compiler tool.
Tell CMake where to find the compiler by setting either the environment
  variable "CC" or the CMake cache entry CMAKE_C_COMPILER to the full path to the compiler, or to the compiler name if it is in the PATH.

CMake Error at CMakeLists.txt:2 (project):
  The CMAKE_CXX_COMPILER:

    /usr/local/bin/c++

  is not a full path to an existing compiler tool.
Tell CMake where to find the compiler by setting either the environment variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path to the compiler, or to the compiler name if it is in the PATH.

-- Configuring incomplete, errors occurred!
See also "/home/pi/ros_catkin_ws/build_isolated/gencpp/CMakeFiles/CMakeOutput.log".
See also "/home/pi/ros_catkin_ws/build_isolated/gencpp/CMakeFiles/CMakeError.log".
Makefile:304: recipe for target 'cmake_check_build_system' failed
make: *** [cmake_check_build_system] Error 1
<== Failed to process package 'gencpp': 
  Command '['/opt/ros/kinetic/env.sh', 'make', 'cmake_check_build_system']' returned non-zero exit status 2

Reproduce this error by running:
==> cd /home/pi/ros_catkin_ws/build_isolated/gencpp && /opt/ros/kinetic/env.sh make cmake_check_build_system

Command failed, exiting.

I have done

sudo apt-get install build_essential
sudo apt-get -f install
sudo apt-get update
sudo apt-get upgrade
export CC=/usr/local/bin/gcc
export CXX=/usr/local/bin/g++

but still get the same error.

How could I resolve this error? I have tried resetting the symbolic links and removing the exports

Answer 1

I think you should unset CC and CXX, or at least use the system compilers, like this (drop the /local):

export CC=/usr/bin/gcc
export CXX=/usr/bin/g++

Answer 2

you need to check where your gcc and g++ located, and make a soft link because i use CentOS

yum -y install centos-release-scl
yum -y install devtoolset-8-gcc devtoolset-8-gcc-c++ devtoolset-8-binutils

to install the gcc so I need to do the following to avoid the same error as you

sudo ln -s /opt/rh/devtoolset-8/root/usr/bin/gcc /usr/bin/cc
sudo ln -s /opt/rh/devtoolset-8/root/usr/bin/g++ /usr/bin/c++

Answer 3

I had similar error while installing openCV 4.2.0 with cuda 10.2 on ubuntu 18.04. I rectified it by(change the gcc/g++ version accordingly)

sudo apt install gcc-6 g++-6

Answer 4

All of the above suggestions din't solve the problem for me at Ubuntu 18.04, It worked for me using:

sudo update-alternatives --install /usr/bin/cc cc /usr/bin/gcc-7 70

After I already had:

sudo update-alternatives --install /usr/bin/c++ g++ /usr/bin/g++-7 10
sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 70

Answer 5

I gone through the problem when compiling opencv with cuda optimization. The compiler issued this message:

The CMAKE_C_COMPILER:
/usr/bin/gcc-6
is not a full path to an existing compiler tool.

The message actually is clear as it simply tells that it doesn't find gcc-6 at the indicated location which in this case is /usr/bin/gcc-6. To verified this I navigated into /usr/bin/ folder and ran the command ls gcc* to see all available gcc GNU C Compilers.

As one can see they were not gcc-6 available but instead gcc-9. Thus, I just had to indicate the relevant path -D CMAKE_C_COMPILER=/usr/bin/gcc-9 and every thing worked find. Note that In case there is any gcc GNU C complier present in /usr/bin/gcc-6 it mean that it no install and you will have to install it and compile opencv again.

Answer 6

I have seen the same symptoms if you have build folders left behind from a build in a different environment (ie switching from local to a container, or between different container variants).

Ensure that you clean the generated build before retrying as it will cache locations to things it can no longer find.