build: FAILED conformance/interfaces/timer_settime/5-1: build: FAILED: Compiler output: conformance/interfaces/timer_settime/5-1.c:41:18: error: variable has incomplete type 'struct sigevent' struct sigevent ev; ^ conformance/interfaces/timer_settime/5-1.c:41:9: note: forward declaration of 'struct sigevent' struct sigevent ev; ^ conformance/interfaces/timer_settime/5-1.c:48:20: error: use of undeclared identifier 'SIGEV_SIGNAL' ev.sigev_notify = SIGEV_SIGNAL; ^ conformance/interfaces/timer_settime/5-1.c:63:6: warning: implicit declaration of function 'timer_create' is invalid in C99 [-Wimplicit-function-declaration] if (timer_create(CLOCK_REALTIME, &ev, &tid) != 0) { ^ conformance/interfaces/timer_settime/5-1.c:82:6: warning: implicit declaration of function 'timer_settime' is invalid in C99 [-Wimplicit-function-declaration] if (timer_settime(tid, flags, &its, NULL) != 0) { ^ conformance/interfaces/timer_settime/5-1.c:92:7: warning: absolute value function 'abs' given an argument of type 'long long' but has parameter of type 'int' which may cause truncation of value [-Wabsolute-value] if ( abs(tsleft.tv_sec-SLEEPDELTA) <= ACCEPTABLEDELTA) { ^ conformance/interfaces/timer_settime/5-1.c:92:7: note: use function 'llabs' instead if ( abs(tsleft.tv_sec-SLEEPDELTA) <= ACCEPTABLEDELTA) { ^~~ llabs 3 warnings and 2 errors generated.