Crash: debugger-agent: Unable to listen on 6

I'm running a OSX build with Jenkins to execute some tests (Unity 2018.2.7f1). The build starts and runs for a few seconds, then exits with this on Player.log:

debugger-agent: Unable to listen on 6
##utp:{"type":"MemoryLeaks","allocatedMemory":414180,"memoryLabels":[{"Default":1664},{"NewDelete":350144},{"Thread":880},{"Manager":112},{"GfxDevice":6640},{"GfxThread":256},{"FMOD":664},{"Serialization":40},{"String":4727},{"DynamicArray":80},{"Sprites":64},{"CloudService":1080},{"WebRequest":47517},{"VR":64},{"SceneManager":480},{"SceneLoad":-240},{"Secure":8}]}

Any clues?

 

Necropost, but basically this message is not causing the build to fail: https://forum.unity.com/threads/6572-debugger-agent-unable-to-listen-on-27.500387/