Hi. The CLOCK_MONOTONIC facility was added in OSX 10.12; the version of OSX you're using is too old to build QEMU on, I'm afraid. QEMU's policy is to support the last two releases of OSX, so at the moment that's 10.14 and 10.15. Compiling on older versions might work, but it also might not, as you've discovered.
** Changed in: qemu Status: New => Won't Fix -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1861551 Title: Errors while compiling source Status in QEMU: Won't Fix Bug description: OS type: Mac OS X 10.11.6 List of errors: qemu-io-cmds.c:837:5: warning: implicit declaration of function 'clock_gettime' is invalid in C99 [-Wimplicit-function-declaration] clock_gettime(CLOCK_MONOTONIC, &t1); ^ qemu-io-cmds.c:837:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t1); ^ qemu-io-cmds.c:843:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t2); ^ qemu-io-cmds.c:970:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t1); ^ qemu-io-cmds.c:972:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t2); ^ qemu-io-cmds.c:1184:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t1); ^ qemu-io-cmds.c:1194:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t2); ^ qemu-io-cmds.c:1306:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t1); ^ qemu-io-cmds.c:1308:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t2); ^ qemu-io-cmds.c:1351:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t2); ^ qemu-io-cmds.c:1383:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t2); ^ qemu-io-cmds.c:1518:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &ctx->t1); ^ qemu-io-cmds.c:1663:23: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &ctx->t1); ^ qemu-io-cmds.c:1885:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t1); ^ qemu-io-cmds.c:1887:19: error: use of undeclared identifier 'CLOCK_MONOTONIC' clock_gettime(CLOCK_MONOTONIC, &t2); ^ 1 warning and 14 errors generated. make: *** [qemu-io-cmds.o] Error 1 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1861551/+subscriptions