v15.0.0rc2

This release implements protocol 15 and supersedes all previous releases.

Protocol 15 addresses issues found during the final validation testing of protocol 14. There are no functional changes compared to protocol 14 from users point of view.

Stability improvements

• Fixed a critical bug in RevokeSponsorshipOp that was found while performing additional testing/audit.
• Fast fail duplicate leader election when running the nomination protocol. This fixes a long standing issue for small networks (like testnet) to sometimes stutter during nomination.
• Fixed an issue where the verify-checkpoint command would deadlock
• Reduce the number of historical SCP messages fetched from peers by default. In particular, this reduces the initial amount of traffic when nodes establish connections by over 80%.
• Do not send duplicate SCP traffic when in sync
• Further improvement in how we output JSON objects
• Improved error messages when quorum sets are misconfigured. Contributed by drey.
• Avoid initiating connections that would fail right away.

New features

• Added a new protocol 14 invariant checker that can be enabled on “super validators”.
• Added a mechanism to override the hash function used in SCP. This makes it easier to use SCP in other projects. Contributed by drey.
• Added additional logging to help track cost associated with other nodes in the quorum. This should help node operators tweak their quorum configuration when things don’t work as expected.

Breaking changes

• We now globally use /dev/stdin instead of - this allows all commands to use standard input as expected. This works around a bug in the command line parser that we use.