P4TRUST
When Swarm is configured to connect to a Helix Versioning Engine
(p4d) using an SSL connection, Swarm automatically
executes the p4 trust command, which accepts the SSL
fingerprint and creates the file data/p4trust
containing a list of trusted servers and their fingerprints. If the
certificate that p4d uses is changed for any reason, when
p4d is restarted Swarm connections to
p4d fail.
The solution is to delete data/p4trust
. On the next
request to Swarm, p4 trust is again automatically
executed and Swarm can then connect to p4d.