Ninja build does not work for coverage target

[ahueck]

Building TypeART with ninja works but executing the (lcov) coverage targets fails (e.g., lcov-make).

Most likely this behavior comes from differences between make and ninja w.r.t. commands in add_custom_target, see https://gitlab.kitware.com/cmake/cmake/-/issues/21778

The respective targets have to be re-worked for ninja-compat.

Update

Ninja doesn't like the lcov-make target, in particular, both the fragments --no-extenal and -b ${CMAKE_SOURCE_DIR}.
What seems to work is:

add_custom_target(
  lcov-make
  COMMAND ${LCOV_COMMAND} ${GCOV_TOOL} ${GCOV_WORKAROUND} -c -d ${CMAKE_BINARY_DIR} -o typeart.coverage
  COMMAND ${LCOV_COMMAND} --remove typeart.coverage '${CMAKE_BINARY_DIR}/*' -o typeart.coverage
  # need to remove externals:
  COMMAND ${LCOV_COMMAND} --remove typeart.coverage '/usr/*' -o typeart.coverage
  COMMAND ${LCOV_COMMAND} --remove typeart.coverage '*/llvm/*' -o typeart.coverage
)