Backport PR #43553 on branch 1.3.x (REGR: Outer merge failing with integer and NaN keys)
Backport PR #43553: REGR: Outer merge failing with integer and NaN keys
> intersphinx inventory 'https://www.statsmodels.org/devel/objects.inv' not fetchable due to <class 'requests.exceptions.ConnectionError'>: HTTPSConnectionPool(host='www.statsmodels.org', port=443): Max retries exceeded with url: /devel/objects.inv (Caused by NewConnectionError('<urllib3.connection.HTTPSConnection object at 0x7f7e2df00e50>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution'


showing up again but ignoring.