===> Building for lockf-1
gcc -o lockf lockf.c
lockf.c: In function 'acquire_lock':
lockf.c:167:40: error: 'O_EXLOCK' undeclared (first use in this function)
lockf.c:167:40: note: each undeclared identifier is reported only once for each function it appears in
lockf.c: At top level:
lockf.c:206:17: error: expected ';', ',' or ')' before '__unused'
lockf.c: In function 'wait_for_lock':
lockf.c:230:32: error: 'O_EXLOCK' undeclared (first use in this function)
lockf.c: At top level:
lockf.c:43:13: warning: 'timeout' used but never defined
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/sysutils/lockf
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/sysutils/lockf