https://bugs.gentoo.org/879699
--- a/configure.ac
+++ b/configure.ac
@@ -156,7 +156,7 @@ AC_MSG_CHECKING(for CLOCK_MONOTONIC)
 AC_TRY_RUN([
   #include <time.h>
   #include <errno.h>
-main()
+int main()
   {
   struct timespec tp;
   if(clock_gettime(CLOCK_MONOTONIC, &tp))