Possible Safety Violation ...

[JoshOrndorff]

Following the instructions in the readme (along with the workaround described in #25). I'm able to start a collator and register it with the relay chain.

Upon successful registration, the collator starts producing blocks, but also starts printing the log message Possible safety violation: attempted to re-finalize last finalized block 0x1ba54575ff754aafb1b468b7da21d7c6555daf0fc292cf80565960797dbdd981.

Full logs:

Cumulus Test Parachain Collator
2019-11-29 12:20:38   version 0.1.0-x86_64-linux-gnu
2019-11-29 12:20:38   by Parity Technologies <admin@parity.io>, 2019
2019-11-29 12:20:38 Chain specification: Local Testnet
2019-11-29 12:20:38 Node name: standing-rings-5270
2019-11-29 12:20:38 Roles: FULL
2019-11-29 12:20:38 Parachain id: Id(0)
2019-11-29 12:20:38 Highest known block at #0
2019-11-29 12:20:38 Using default protocol ID "sup" because none is configured in the chain specs
2019-11-29 12:20:38 Local node identity is: QmVi1qo3rrcqVAFZtJKETnQ3SmEdZcHuQ19BAm3dMt9k3C
2019-11-29 12:20:38 Not registering Substrate logger, as there is already a global logger registered!
2019-11-29 12:20:39 Cumulus Test Parachain Collator
2019-11-29 12:20:39   version 0.1.0-x86_64-linux-gnu
2019-11-29 12:20:39   by Parity Technologies <admin@parity.io>, 2017-2019
2019-11-29 12:20:39 Chain specification: Local Testnet
2019-11-29 12:20:39 Node name: well-off-hall-2350
2019-11-29 12:20:39 Roles: FULL
2019-11-29 12:20:39 Highest known block at #323
2019-11-29 12:20:39 Local node identity is: QmVj4EZKV9AEHeDs43JLFauDdGAU6Lho83xyaZQXeigUFN
2019-11-29 12:20:39 Can't listen on /ip4/0.0.0.0/tcp/30333 because: Other(Custom { kind: Other, error: Other(A(A(A(B(Underlying(B(Os { code: 98, kind: AddrInUse, message: "Address already in use" }))))))) })
2019-11-29 12:20:39 Unable to bind server to 127.0.0.1:9955. Trying random port.
2019-11-29 12:20:42 Imported #330 (0x3a6a…c9a8)
2019-11-29 12:20:44 Idle (1 peers), best: #330 (0x3a6a…c9a8), finalized #329 (0xf2c7…9bd3), ⬇ 1.9kiB/s ⬆ 0.9kiB/s
2019-11-29 12:20:48 Imported #331 (0xb4eb…3291)
2019-11-29 12:20:49 Idle (1 peers), best: #331 (0xb4eb…3291), finalized #330 (0x3a6a…c9a8), ⬇ 0.9kiB/s ⬆ 0.4kiB/s
2019-11-29 12:20:54 Idle (1 peers), best: #331 (0xb4eb…3291), finalized #330 (0x3a6a…c9a8), ⬇ 65.8kiB/s ⬆ 0.2kiB/s
2019-11-29 12:20:55 Imported #332 (0xaaf8…3385)
2019-11-29 12:20:55 Starting consensus session on top of parent 0x6a09b77fced72eec69dd1dd656950fc2406853e5864effe06c7befa2f1c8b372
2019-11-29 12:20:55 Imported #332 (0x7bce…5de3)
2019-11-29 12:20:55 Prepared block for proposing at 1 [hash: 0xa8b930e1297c2ddd4afaf5499ecd6b62d199a621cd16a592150cdf6a405adfc7; parent_hash: 0x6a09…b372; extrinsics: [0xbfe3…a91c]]
2019-11-29 12:20:55 Starting consensus session on top of parent 0x6a09b77fced72eec69dd1dd656950fc2406853e5864effe06c7befa2f1c8b372
2019-11-29 12:20:55 Prepared block for proposing at 1 [hash: 0x0cd7ad590f40364289d7eb5934841c9c25f6a3719c769d01b890d7acb98d97e5; parent_hash: 0x6a09…b372; extrinsics: [0xec3b…3d76]]
2019-11-29 12:20:59 Idle (1 peers), best: #332 (0xaaf8…3385), finalized #331 (0xb4eb…3291), ⬇ 197.5kiB/s ⬆ 0.5kiB/s
2019-11-29 12:21:00 Imported #333 (0x7425…133e)
2019-11-29 12:21:00 Starting consensus session on top of parent 0x6a09b77fced72eec69dd1dd656950fc2406853e5864effe06c7befa2f1c8b372
2019-11-29 12:21:00 Prepared block for proposing at 1 [hash: 0xd2e5e107f55115a2d111befee92a53b98235b285cedcc4c4a204a701c17c28ac; parent_hash: 0x6a09…b372; extrinsics: [0x3b29…325a]]
2019-11-29 12:21:02 Possible safety violation: attempted to re-finalize last finalized block 0x6a09b77fced72eec69dd1dd656950fc2406853e5864effe06c7befa2f1c8b372 
2019-11-29 12:21:04 Idle (1 peers), best: #333 (0x7425…133e), finalized #332 (0xaaf8…3385), ⬇ 66.3kiB/s ⬆ 66.2kiB/s
2019-11-29 12:21:06 Imported #334 (0xadb4…849d)
2019-11-29 12:21:06 Starting consensus session on top of parent 0x6a09b77fced72eec69dd1dd656950fc2406853e5864effe06c7befa2f1c8b372
2019-11-29 12:21:06 Prepared block for proposing at 1 [hash: 0x4d228924a1048d00c9bb4c7818f72cf5915397c8312e4d32e948d918dc38549c; parent_hash: 0x6a09…b372; extrinsics: [0xf17e…a93f]]
2019-11-29 12:21:07 Possible safety violation: attempted to re-finalize last finalized block 0x6a09b77fced72eec69dd1dd656950fc2406853e5864effe06c7befa2f1c8b372