"No such file or directory" errors when running with --output-dir

[netllama]

What's the issue, what's expected?:
Running sb run with the optional --output-dir parameter prevents results from being collected from the test nodes, and instead spews No such file or directory errors from the "Synchronize Output Directory" task

How to reproduce it?:
sb run -f config.ini -c default.yaml --output-dir $ALTERNATE_LOCATION

Log message or shapshot?:

TASK [Synchronize Output Directory] ********************************************
fatal: [2.3.1.2]: FAILED! => {"changed": false, "cmd": "/usr/bin/rsync --delay-updates -F --compress --archive --rsh='/usr/bin/ssh -S none -i /Users/lfriedman/.ssh/id_ecdsa -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null' --exclude=nodes --out-format='<<CHANGED>>%i %n%L' ubuntu@2.3.1.2:/var/folders/lt/2k4v_sdd2ljbbl3c4lw538640000gn/T/tmp.QD5dwUu9UM/sb-run/output/ /private/var/folders/lt/2k4v_sdd2ljbbl3c4lw538640000gn/T/tmp.QD5dwUu9UM/sb-run/output/nodes/chimpanzee-1", "msg": "Warning: Permanently added '2.3.1.2' (ED25519) to the list of known hosts.\r\nrsync: [sender] change_dir \"/var/folders/lt/2k4v_sdd2ljbbl3c4lw538640000gn/T/tmp.QD5dwUu9UM/sb-run/output\" failed: No such file or directory (2)\nrsync(80938): warning: receiver has empty file list: exiting\n", "rc": 23}