CMake: "Import existing build" comes up with a different build dir

Running "/home/nik/usr/cmake-3.7.2-Linux-x86_64/bin/cmake -E server --pipe=/tmp/cmake-OEcuue/socket --experimental" in /tmp/QtCreator-8cdLJm/qtc-cmake-XXTDwOi0.
The C compiler identification is unknown
CMake Error at CMakeLists.txt:47 (project):
  No CMAKE_C_COMPILER could be found.

  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.


Configuring incomplete, errors occurred!
See also "/tmp/QtCreator-8cdLJm/qtc-cmake-XXTDwOi0/CMakeFiles/CMakeOutput.log".
See also "/tmp/QtCreator-8cdLJm/qtc-cmake-XXTDwOi0/CMakeFiles/CMakeError.log".
Running "/home/nik/usr/cmake-3.7.2-Linux-x86_64/bin/cmake -E server --pipe=/tmp/cmake-WaxZwI/socket --experimental" in /tmp/QtCreator-8cdLJm/qtc-cmake-XXTDwOi0.
Running "/home/nik/usr/cmake-3.7.2-Linux-x86_64/bin/cmake -E server --pipe=/tmp/cmake-HJkO7c/socket --experimental" in /home/nik/dev/llvm/4.0/builds/gcc54_rtti_debug.
The C compiler identification is unknown
CMake Error at CMakeLists.txt:47 (project):
  No CMAKE_C_COMPILER could be found.

  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.


Configuring incomplete, errors occurred!
See also "/home/nik/dev/llvm/4.0/builds/gcc54_rtti_debug/CMakeFiles/CMakeOutput.log".
See also "/home/nik/dev/llvm/4.0/builds/gcc54_rtti_debug/CMakeFiles/CMakeError.log".