Avoiding debugging issues¶
When you set a breakpoint, e.g. via
and run a collection of tests,
you may receive the following message:
Can't use pdb.set_trace when running a layer as a subprocess!
This happens when you are running a collection of tests which span multiple layers, and a previous layer could not be safely torn down in-process, so the testrunner had to spawn a subprocess instead.
The workaround is to run just the one test you are trying to debug.
You can read more about this issue in zope.testrunner’s documentation.