- cmake_make_flags="${cmake_make_flags} -j ${cmake_parallel_make}"
+ case "$cmake_parallel_make" in
+ [0-9]*) cmake_parallel_make="-j ${cmake_parallel_make}";;
- cmake_make_flags="${cmake_make_flags} -j ${cmake_parallel_make}"
+ case "$cmake_parallel_make" in
+ [0-9]*) cmake_parallel_make="-j ${cmake_parallel_make}";;