This is a CMake Environment Variable. Its initial value is taken from the calling process environment.
Preferred executable for compiling
CXX language files. Will only be used by
CMake on the first configuration to determine
CXX compiler, after which the
CXX is stored in the cache as
CMAKE_CXX_COMPILER. For any configuration
run (including the first), the environment variable will be ignored if the
CMAKE_CXX_COMPILER variable is defined.
Options that are required to make the compiler work correctly can be included; they can not be changed.
$ export CXX="custom-compiler --arg1 --arg2"