I found one! :-)

A high-level process interrupts the UI process, which just wants to open a debugger and did already raise the recursion flag. That high-level process throws an exception.

Boom. EE comes eagerly but both debuggers could appear side by side.

Best,
Marcel
Am 24.09.2019 14:10:46 schrieb Marcel Taeumel <marcel.taeumel at hpi.de>:
Hi, there.

I am fixing stuff in Morphic and MVC debuggers at the moment. I stumbled upon the ErrorRecursionGuard:
http://forum.world.st/Recovery-project-hanging-after-recursive-error-in-debugger-tp4957808p4958177.html [http://forum.world.st/Recovery-project-hanging-after-recursive-error-in-debugger-tp4957808p4958177.html]

> ErrorRecursionGuard is a _patch_ to a relatively new addition, the
> introduction of Debugger>>'ErrorRecursion' which resulted in the
> Emergency Evaluator being opened too eagerly (and unable to be
> closed!) -- even when there was no recursion. 

I don't see how such a mutex could help preventing EEs opened too eagerly. Yet, I can see many problems arise with it.

I will remove that mutex for now and do some tests. Unless somebody has an explanation how the guard should help against anything. :-)

Best,
Marcel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20190924/4c85d69d/attachment.html>