Add a "fork" of musl as //fusl.

fusl/src/stat/utimensat.c

+#include <sys/stat.h>
+#include <sys/time.h>
+#include <fcntl.h>
+#include <errno.h>
+#include "syscall.h"
+
+int utimensat(int fd, const char *path, const struct timespec times[2], int flags)
+{
+        int r = __syscall(SYS_utimensat, fd, path, times, flags);
+#ifdef SYS_futimesat
+        if (r != -ENOSYS || flags) return __syscall_ret(r);
+        struct timeval *tv = 0, tmp[2];
+        if (times) {
+                int i;
+                tv = tmp;
+                for (i=0; i<2; i++) {
+                        if (times[i].tv_nsec >= 1000000000ULL) {
+                                if (times[i].tv_nsec == UTIME_NOW &&
+                                    times[1-i].tv_nsec == UTIME_NOW) {
+                                        tv = 0;
+                                        break;
+                                }
+                                if (times[i].tv_nsec == UTIME_OMIT)
+                                        return __syscall_ret(-ENOSYS);
+                                return __syscall_ret(-EINVAL);
+                        }
+                        tmp[i].tv_sec = times[i].tv_sec;
+                        tmp[i].tv_usec = times[i].tv_nsec / 1000;
+                }
+        }
+
+        r = __syscall(SYS_futimesat, fd, path, tv);
+        if (r != -ENOSYS || fd != AT_FDCWD) return __syscall_ret(r);
+        r = __syscall(SYS_utimes, path, tv);
+#endif
+        return __syscall_ret(r);
+}