comment #1:

> Using 0 here still gives a random shuffle because 0 means "generate a new random number".  However you're right that this is not correct because it doesn't allow us to recreate the random value.
>
> Thanks for the note!

Should I send my suggested change as a patch to the mailing list or is a different approach preferred?

When using submake it seems the seed isn't getting set properly as MAKEFLAGS just gets passed "--shuffle=0" when the toplevel make is invoked with "--shuffle=random".

I think we need to do something like this so that we initialize the seed before it gets passed to MAKEFLAGS:
diff --git a/src/shuffle.c b/src/shuffle.c
index 4cfdc943..471c56b1 100644
--- a/src/shuffle.c
+++ b/src/shuffle.c
@@ -82,7 +82,11 @@ shuffle_set_mode (const char *cmdarg)
     }
   else
     {
-      if (strcasecmp (cmdarg, "random") != 0)
+      if (strcasecmp (cmdarg, "random") == 0)
+        {
+          config.seed = make_rand ();
+        }
+      else
         {
           /* Assume explicit seed.  */
           const char *err;