Skip network tests when getaddrinfo() returns EAI_AGAIN, meaning a temporary

failure in name resolution.

Should fix a buildbot failure.

Lib/test/support.py

@@ -909,6 +909,7 @@ def transient_internet(resource_name, *, timeout=30.0, errnos=()):
         ('ETIMEDOUT', 110),
     ]
     default_gai_errnos = [
+        ('EAI_AGAIN', -3),
         ('EAI_NONAME', -2),
         ('EAI_NODATA', -5),
         # Encountered when trying to resolve IPv6-only hostnames

Misc/NEWS

@@ -1008,6 +1008,9 @@ Extension Modules
 Tests
 -----
 
+- Skip network tests when getaddrinfo() returns EAI_AGAIN, meaning a temporary
+  failure in name resolution.
+
 - Avoid failing in test_robotparser when mueblesmoraleda.com is flaky and
   an overzealous DNS service (e.g. OpenDNS) redirects to a placeholder
   Web site.