Cannot resolve docker.local: Unknown host

Beta9 actually introduced this for me. I cannot ping docker.local and none of my docker backed services can connect. HELP!

$ pinata diagnose
OS X: version 10.11.4 (build: 15E65) version v1.11.0-beta9
Running diagnostic tests:
[OK]      docker-cli
[OK]      Moby booted
[OK]      driver.amd64-linux
[OK]      vmnetd
[OK]      osxfs
[OK]      db
[OK]      slirp
[OK]      menubar
[OK]      environment
[OK]      Docker
[OK]      VT-x
Docker logs are being collected into /tmp/20160429-095823.tar.gz
Most specific failure is: No error was detected
Would you like to upload log files? [Y/n]: Y

Your unique id is: 8067B04A-FEE5-43FF-AAF0-B5A11BD25D7F
Please quote this in all correspondence.
$ ping docker.local
ping: cannot resolve docker.local: Unknown host