It seems like test_urllib2net.test_ftp_no_timeout() has no timeout: it should use a timeout to not block the whole test suite if the FTP server is down.

x86 Gentoo Non-Debug with X 3.7:
https://buildbot.python.org/all/#/builders/115/builds/1044

0:26:50 load avg: 1.68 [413/416] test_genericpath passed -- running: test_urllib2net (11 min 59 sec)
0:26:52 load avg: 1.68 [414/416] test_tempfile passed -- running: test_urllib2net (12 min 1 sec)
0:26:52 load avg: 1.68 [415/416] test_pipes passed -- running: test_urllib2net (12 min 1 sec)
running: test_urllib2net (12 min 31 sec)
running: test_urllib2net (13 min 1 sec)
running: test_urllib2net (13 min 31 sec)
running: test_urllib2net (14 min 1 sec)
running: test_urllib2net (14 min 31 sec)
0:29:51 load avg: 1.49 [416/416/1] test_urllib2net crashed (Exit code 1)
Timeout (0:15:00)!
Thread 0xb7be2700 (most recent call first):
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/socket.py", line 716 in create_connection
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/ftplib.py", line 152 in connect
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 2384 in init
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 2375 in __init__
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 1555 in connect_ftp
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 1533 in ftp_open
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 503 in _call_chain
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 543 in _open
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 525 in open
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/urllib/request.py", line 222 in urlopen
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/test/test_urllib2net.py", line 19 in _retry_thrice
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/test/test_urllib2net.py", line 27 in wrapped
  File "/buildbot/buildarea/cpython/3.7.ware-gentoo-x86.nondebug/build/Lib/test/test_urllib2net.py", line 327 in test_ftp_no_timeout