This has bugged me a few times recently, so I've produced a demo.

Define...

�� Object subclass: #AA

instanceVariableNames: ''

classVariableNames: ''

package: 'AAAA'

�� AA>>test

self haltOnce.

self inform: 'I got here'.

then in playground evaluate....

�� Halt resetOnce. "i.e. World > Debugging > Enable all break/inspect once."

�� AA new test.

and as expected you get a debugger window.

Now once again��without closing the debugger ...

�� Halt resetOnce.��

�� AA new test.

and I'd expect another debugger, but instead I'm informed 'I got here'.

Its extremely useful sometimes to parallel trace through code comparing two cases,

and the current behaviour prevents that. .

The Pharo 5��equivalent works as expected...

�� Halt enableHaltOnce.��

�� AA new test.

I'm not sure where to hang it, but the following test��

differentiates between Pharo 5 & 6. (you can also run it from the playground.)

��

��testParallelTrace

�� �� |completed p1 ds1��p2��ds2|

�� �� completed := 0.��

�� �� Halt resetOnce. "enableHaltOnce"

�� �� p1 := [ self haltOnce. completed := completed + 1 ] newProcess.

�� �� ds1 := DebugSession named: 'Trace1' on: p1 startedAt: p1 suspendedContext.

�� �� ds1 resume.

�� �� Halt resetOnce. "enableHaltOnce"

�� �� p2 := [ self haltOnce. completed := completed + 1 ] newProcess.

�� �� ds2 := DebugSession named: 'Trace2' on: p2 startedAt: p2 suspendedContext.

�� �� ds2 resume.

�� �� self assert: (completed = 0)��

I've opened��

https://pharo.fogbugz.com/f/cases/19677/Cannot-parallel-trace-through-same-method

cheers -ben

P.S. I'm not sure if enabling the global haltOnce might cause issues. ��

It would be useful to be able to set it only for the DebugSession.