error: In attribute 'servers', Scalar value is out of range

I have the following body that works in 3.5.2 but fails in 3.6 beta 2.

<pre>
[root@esv4-cfe-test inputs]# /var/cfengine/bin/cf-agent -I -K -f failsafe.cf
2014-03-27T07:27:35-0700 error: /default/copy_md5sum_generated_data/files/'/var/cfengine/md5_digest'[0]: /var/cfengine/inputs/scale_cfengine_data_transfers.cf:516:0: error: In attribute 'servers', Scalar value is out of range

502 body copy_from quad_remote_copy(sourcedir,mps1,mps2,mps3,mps4)
503 {
504 source => "$(sourcedir)";
505 copy_backup => "true";
506 purge => "true";
507 trustkey => "true";
508 compare => "digest";
509 encrypt => "true";
510 verify => "true";
511
512 mps1_primary::
513 servers =>

{"$(mps1)", "$(mps2)", "$(mps3)", "$(mps4)" }

;
514
515 mps2_primary::
516 servers =>

{"$(mps2)", "$(mps3)", "$(mps4)", "$(mps1)" }

;
517
518 mps3_primary::
519 servers =>

{"$(mps3)", "$(mps4)", "$(mps1)", "$(mps2)" }

;
520
521 mps4_primary::
522 servers =>

{"$(mps4)", "$(mps1)", "$(mps2)", "$(mps3)" }

;
523 }

</pre>