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

fusl/src/stdio/tmpnam.c

+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <string.h>
+#include "syscall.h"
+
+#define MAXTRIES 100
+
+char *__randname(char *);
+
+char *tmpnam(char *buf)
+{
+        static char internal[L_tmpnam];
+        char s[] = "/tmp/tmpnam_XXXXXX";
+        int try;
+        int r;
+        for (try=0; try<MAXTRIES; try++) {
+                __randname(s+12);
+#ifdef SYS_lstat
+                r = __syscall(SYS_lstat, s, &(struct stat){0});
+#else
+                r = __syscall(SYS_fstatat, AT_FDCWD, s,
+                        &(struct stat){0}, AT_SYMLINK_NOFOLLOW);
+#endif
+                if (r == -ENOENT) return strcpy(buf ? buf : internal, s);
+        }
+        return 0;
+}