Return Error Code After Unit Tests to CircleCI Job

Does anyone have experience with CircleCI or really any automation tool using %UnitTest?

I have built my app and ran my unit test in a Docker container automated by CircleCI.  However, after many of the tests failed I see:

How do you halt out of the IRIS session and return an exit code to the shell?

I have a script in my repo that I pass into IRIS after CircleCI does the code checkout

iris session IRIS < inFile

Am I trying to approach this the wrong way?  Should I be writing test output to a file or something?  Even so, I still need a way to say to CirclCI "unit tests failed, so don't do the next step of building the code on the actual server" and to send out alerts so we know it failed.