debugpy: FTBFS due to either "Timed out..." or "Address already in use"

debugpy is currently FTBFSing:

https://launchpadlibrarian.net/628844384/buildlog_ubuntu-kinetic-amd64.debugpy_1.6.3+ds-1_BUILDING.txt.gz

E+00015.109: /handling #2 request "attach" from Client[1]/
             Traceback (most recent call last):
               File "/<<PKGBUILDDIR>>/.pybuild/cpython3_3.10_debugpy/build/debugpy/adapter/../../debugpy/common/messaging.py", line 1015, in __init__
                 raise self
             debugpy.common.messaging.MessageHandlingError: Timed out waiting for debug server to connect.

Locally, I can reproduce the failure but I see a different error:

E+00000.008: Error listening for incoming Client connections on 127.0.0.1:5684:

             Traceback (most recent call last):
               File "/<<PKGBUILDDIR>>/.pybuild/cpython3_3.10_debugpy/build/debugpy/../debugpy/adapter/../../debugpy/common/sockets.py", line 93, in serve
                 listener = create_server(host, port, backlog, timeout)
               File "/<<PKGBUILDDIR>>/.pybuild/cpython3_3.10_debugpy/build/debugpy/../debugpy/adapter/../../debugpy/common/sockets.py", line 24, in create_server
                 server.bind((host, port))
             OSError: [Errno 98] Address already in use

This is impacting ipykernel and possibly other packages.