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

fusl/src/time/__asctime.c

+#include <time.h>
+#include <stdio.h>
+#include <langinfo.h>
+#include "atomic.h"
+
+const char *__nl_langinfo(nl_item);
+
+char *__asctime(const struct tm *restrict tm, char *restrict buf)
+{
+        /* FIXME: change __nl_langinfo to __nl_langinfo_l with explicit C
+         * locale once we have locales */
+        if (snprintf(buf, 26, "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n",
+                __nl_langinfo(ABDAY_1+tm->tm_wday),
+                __nl_langinfo(ABMON_1+tm->tm_mon),
+                tm->tm_mday, tm->tm_hour,
+                tm->tm_min, tm->tm_sec,
+                1900 + tm->tm_year) >= 26)
+        {
+                /* ISO C requires us to use the above format string,
+                 * even if it will not fit in the buffer. Thus asctime_r
+                 * is _supposed_ to crash if the fields in tm are too large.
+                 * We follow this behavior and crash "gracefully" to warn
+                 * application developers that they may not be so lucky
+                 * on other implementations (e.g. stack smashing..).
+                 */
+                a_crash();
+        }
+        return buf;
+}