patch 7.4.1276
Problem:    Warning for not using return value of fcntl().
Solution:   Explicitly ignore the return value.
diff --git a/src/fileio.c b/src/fileio.c
index ecec757..f0ef675 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2350,7 +2350,7 @@
     {
 	int fdflags = fcntl(fd, F_GETFD);
 	if (fdflags >= 0 && (fdflags & FD_CLOEXEC) == 0)
-	    fcntl(fd, F_SETFD, fdflags | FD_CLOEXEC);
+	    (void)fcntl(fd, F_SETFD, fdflags | FD_CLOEXEC);
     }
 #endif
     vim_free(buffer);