In Pharo 5, it was possible to do... TestCase subclass: #Example ....etc Example >> test1 [ Transcript crShow: Processor activeProcess priority printString; tab; show: Processor activeProcess name. self halt. Transcript crShow: Processor activeProcess effectiveProcess priority printString; tab; show: Processor activeProcess effectiveProcess name ] forkAt: 39 named: 'TEST'. ...and when this was run, a debugger would show for the forked code and stepping through it would produce the following output... 39 TEST 39 TEST In Pharo 71047, no debugger shows up, and you only get one... 39 TEST I guess this because more cleanup of tests is being done, but it makes it harder to debug multi-threaded tests when debugger can't replicate the way the code normally runs. cheers -ben