ninja cannot erase folder with more than 1 generated file inside
Arch with CMake 3.8.2.
add_custom_command(OUTPUT ${foo_dir}
COMMAND ${CMAKE_COMMAND} -E make_directory ${foo_dir}
)
add_custom_target(foo_dir_target DEPENDS ${foo_dir})
add_custom_command(OUTPUT ${foo_dir}/foo.cpp
COMMAND ${CMAKE_COMMAND} -E touch ${foo_dir}/foo.cpp
DEPENDS foo_dir_target
)
add_custom_command(OUTPUT ${foo_dir}/foo2.cpp
COMMAND ${CMAKE_COMMAND} -E touch ${foo_dir}/foo2.cpp
DEPENDS foo_dir_target
)
mkdir build; cd build; cmake -G Ninja ..; cmake --build .; cmake --build . --target clean;
ninja: error: remove(foo): Directory not empty