cmake add_custom_command failure, target gets deleted

Question

I am building a test executable using CMake. During the build process, I would like to run the executable, which returns whether the tests pass or not. If not, I would like the build to fail. However, when I use add_custom_command(... POST_BUILD ... ), and use a Makefile generator, the test executable will be deleted (explain in this question: Why does GNU make delete a file).

Is there a way to have CMake treat the executable as a .PRECIOUS, or otherwise change the CMakeLists.txt such that the executable doesn't get deleted if the tests fail?

For reference, my CMakeList.txt looks like the following (simplified from actual):

add_executable(UnitTest unittest.cpp)
add_custom_command(TARGET UnitTest POST_BUILD COMMAND $<TARGET_FILE:UnitTest>)

Answer 1

The solution that I was alluding to was to use add_custom_target instead of add_custom_command. While it will not delete the executable if the test fails and the build process as a whole fails if runUnitTest fails, this target does not get built as a result of building the UnitTest target specifically.

add_executable(UnitTest unittest.cpp)
add_custom_target(runUnitTest UnitTest COMMAND $<TARGET_FILE:UnitTest> DEPENDS UnitTest)