On some of the linux boxes on our (air-gapped, if that matters) network it looks like some of them were mis-configured and their /etc/hosts file looks something like this:

$ cat /etc/hosts
127.0.0.1 snoopy.the.internal.domain snoopy localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6

... whereas for other linux machines not exhibiting this problem:

$ cat /etc/hosts
127.0.0.1 woodstock.the.internal.domain woodstock localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6

It appears this is causing test_logging to hang while running SocketHandlerTest.

Unfortunately I don't have administrative privileges so I'm not able to prove I'm right.  I only have circumstantial evidence, but no machine I tested (about 20 machines) contradicts what I stated above.

The same bug for me:
3.6.5 and 3.6.4 -hangs on test_logging forever.

Thanks to this report - I've commented some lines in /etc/host
and after 'test_logging' passed OK!

I confirm the issue. test_logging hangs if the resolution of the hostname fails with a timeout.

I worked again the issue by adding my hostname to /etc/hosts.