Descriptors (e.g. properties) such as in the added test case are
triggered during collection, executing arbitrary code which can raise.
Previously, such exceptions were propagated and failed the collection.
Now these exceptions are caught and the corresponding attributes are
silently ignored.
A better solution would be to completely skip access to all custom
descriptors, such that the offending code doesn't even trigger. However
I think this requires manually going through the instance and all of its
MRO for each and every attribute checking if it might be a proper
fixture before accessing it. So I took the easy route here.
In other words, putting something like this in your test class is still
a bad idea...:
@property
def innocent(self):
os.system('rm -rf /')
Fixes#2234.
KeyboardInterrupt is a subclass of BaseException, but not of Exception.
Hence if we remove this except, KeyboardInterrupts will still be raised
so the behavior stays the same.
