In file included from /usr/include/assert.h:35, from functest_strlcpy.c:3: /usr/include/features.h:413:4: warning: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Wcpp] 413 | # warning _FORTIFY_SOURCE requires compiling with optimization (-O) | ^~~~~~~ functest_strlcpy.c: In function 'main': functest_strlcpy.c:28:3: warning: assignment to 'char (*)()' from 'char' makes pointer from integer without a cast [-Wint-conversion] 28 | f = strlcpy (); | ^ /usr/bin/ld: /tmp/cc26Lm9Z.o: in function `main': functest_strlcpy.c:(.text+0xa): undefined reference to `strlcpy' collect2: error: ld returned 1 exit status