skip timing test on macos

ci/test-04-options-a-b.pl

@@ -85,7 +85,10 @@ $cmd->stderr_is_eq("");
 }
 
 # fping -B
-{
+SKIP: {
+    if($^O eq 'darwin') {
+        skip 'timing test not reliable on macOS', 5;
+    }
     my $t0 = [gettimeofday];
     my $cmd = Test::Command->new(cmd => "fping  -t 100 -r 3 -B 2  8.8.8.7");
     $cmd->exit_is_num(1);