Sometimes running xcode test on CLI returns "manager not ready"

I normally run my xcode unit tests on command line using these commands:

clean:

xcodebuild -workspace appName.xcworkspace -scheme "Shared appName" -destination "platform=iOS Simulator,name=iPhone 5s,OS=8.1" clean

then build:

xcodebuild -workspace appName.xcworkspace -scheme "Shared appName" -destination "platform=iOS Simulator,name=iPhone 5s,OS=8.1" build

then test (with dry run):

xcodebuild -workspace appName.xcworkspace -scheme "Shared appName" -destination "platform=iOS Simulator,name=iPhone 5s,OS=8.1" test -dry-run

and I sometimes I get this error:

2015-02-27 11:01:50.417 Registering for testmanagerd availability notify post.
2015-02-27 11:01:50.417 testmanagerd availability notify_get_state check indicated manager not ready, waiting for notify post.
2015-02-27 11:02:50.371 60s elapsed since launch without testing starting, sending logs to stderr

any idea how to prevent this from happening? I'm assuming that the testmanagerd is a test daemon or something? Where can I find documentation about that?