I have no idea why this is only happening now but this error was seen after multiple attempts to test the branch cut job on releases-jenkins.
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/requests/adapters.py", line 439, in send
resp = conn.urlopen(
File "/usr/lib/python3/dist-packages/urllib3/connectionpool.py", line 755, in urlopen
retries = retries.increment(
File "/usr/lib/python3/dist-packages/urllib3/util/retry.py", line 574, in increment
raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='gerrit.wikimedia.org', port=443): Max retries exceeded with url: /r/a/changes/1070971/detail (Caused by ProxyError('Cannot connect to proxy.', RemoteDisconnected('Remote end closed connection without response')))After investigation by myself and @hashar it seems the Puppet managed environment (including NO_PROXY) in /etc/environment.d/10-base-wmf-environment.conf does not effect the Jenkins job environments.
I confirmed that manually specifying NO_PROXY=gerrit.wikimedia.org in the job avoids the problem, so we should add that to the job definition. Using the same value that Puppet sets up makes sense.