int i, errs;
        struct remote *remote = remote_get(repo);
 
-       if (!remote)
-               die("bad repository '%s'", repo);
+       if (!remote) {
+               if (repo)
+                       die("bad repository '%s'", repo);
+               die("No destination configured to push to.");
+       }
 
        if (remote->mirror)
                flags |= (TRANSPORT_PUSH_MIRROR|TRANSPORT_PUSH_FORCE);
 
-       if ((flags & (TRANSPORT_PUSH_ALL|TRANSPORT_PUSH_MIRROR)) && refspec)
-               return -1;
+       if ((flags & TRANSPORT_PUSH_ALL) && refspec) {
+               if (!strcmp(*refspec, "refs/tags/*"))
+                       return error("--all and --tags are incompatible");
+               return error("--all can't be combined with refspecs");
+       }
+
+       if ((flags & TRANSPORT_PUSH_MIRROR) && refspec) {
+               if (!strcmp(*refspec, "refs/tags/*"))
+                       return error("--mirror and --tags are incompatible");
+               return error("--mirror can't be combined with refspecs");
+       }
 
        if ((flags & (TRANSPORT_PUSH_ALL|TRANSPORT_PUSH_MIRROR)) ==
                                (TRANSPORT_PUSH_ALL|TRANSPORT_PUSH_MIRROR)) {