I've tried this with CMake 3.5 and 3.11, on GNU/Linux systems. If I have a simple CMakeLists.txt file: ``` $ cd /tmp/obj $ cat ../src/CMakeLists.txt PROJECT(foobar) CMAKE_MINIMUM_REQUIRED(VERSION 3.0) ``` Then I run `cmake` while overriding any of the variables in the subject: ``` $ type -a mklib /tools/bin/mklib $ mklib mklib version 1.0 $ cmake CMAKE_AR=mklib ../src ``` Then cmake does completely the wrong thing and assumes that this tool exists in the local directory rather than on the PATH where it really exists: ``` $ grep mklib CMakeCache.txt CMAKE_AR:FILEPATH=/tmp/obj/mklib //ADVANCED property for variable: CMAKE_AR CMAKE_AR-ADVANCED:INTERNAL=1 ``` This obviously causes my builds to fail since that binary doesn't exist at that path. The same behavior happens for the `CMAKE_LINKER`, `CMAKE_RANLIB`, `CMAKE_STRIP`, and `CMAKE_OBJCOPY` variable assignments. Oddly, the `CMAKE_C_COMPILER` and `CMAKE_CXX_COMPILER` variables do work properly (that is, if I override them with a simple command name that command is looked up in the `PATH` and the correct value is substituted rather than assuming the local directory).