User_KP compiler fault

[nekser]

Trying to build tests/user_kp, there is the following error:

smart-trip/tests/user_kp$ make
[ 25%] Built target ontology
[ 50%] Building C object common/CMakeFiles/commons.dir/st_point.c.o
smart-trip/common/st_point.c: In function ‘st_free_point_array’:
smart-trip/common/st_point.c:25:5: error: ‘for’ loop initial declarations are only allowed in C99 mode
for (int i = 0; i < size; i++) {
^
smart-trip/common/st_point.c:25:5: note: use option -std=c99 or -std=gnu99 to compile your code
make[2]: *** [common/CMakeFiles/commons.dir/st_point.c.o] Error 1
make[1]: *** [common/CMakeFiles/commons.dir/all] Error 2
make: *** [all] Error 2

Possible solution, I found is to add
set (CMAKE_C_FLAGS "--std=gnu99 ${CMAKE_C_FLAGS}")
to tests/user_kp/CMakeLists.txt