Panic on a standalone transcoder, when tearing down the session

[cyberj0g]

The errors seem to be specifically related to tearing down unused session from untrusted pool here, when fast verification is enabled. When fast verification is not enabled, this code path is not invoked, because only one session is selected from the pool.

Jan 24 19:53:09 BenNJ videominer[4170691]: I0124 19:53:09.068891 4170691 lb.go:72] manifestID=056eef72-7b9c-4088-a8cf-856050d89712 seqNo=9188 orchSessionID=1bc3a798 taskId=22254 LB: Using existing transcode session for key=1bc3a798_1
Jan 24 19:53:09 BenNJ videominer[4170691]: I0124 19:53:09.068904 4170691 lb.go:232] manifestID=056eef72-7b9c-4088-a8cf-856050d89712 seqNo=9188 orchSessionID=1bc3a798 taskId=22254 LB: Transcode submitted for key=1bc3a798_1
Jan 24 19:53:09 BenNJ videominer[4170691]: panic: close of closed channel
Jan 24 19:53:09 BenNJ videominer[4170691]: goroutine 68 [running]:
Jan 24 19:53:09 BenNJ videominer[4170691]: github.com/livepeer/go-livepeer/core.(*LoadBalancingTranscoder).EndTranscodingSession(0x0?, {0xc000bba1a0, 0x8})
Jan 24 19:53:09 BenNJ videominer[4170691]:         /home/runner/work/Videominer-Pool/Videominer-Pool/core/lb.go:47 +0xed
Jan 24 19:53:09 BenNJ videominer[4170691]: github.com/livepeer/go-livepeer/server.runTranscoder(0xc000192180, {0xc00013e068, 0x21}, 0xa, {0xc00016d700, 0xf, 0x10}, {0xe1, 0x3c, 0x31, ...})
Jan 24 19:53:09 BenNJ videominer[4170691]:         /home/runner/work/Videominer-Pool/Videominer-Pool/server/ot_rpc.go:148 +0x82f
Jan 24 19:53:09 BenNJ videominer[4170691]: github.com/livepeer/go-livepeer/server.RunTranscoder.func1()
Jan 24 19:53:09 BenNJ videominer[4170691]:         /home/runner/work/Videominer-Pool/Videominer-Pool/server/ot_rpc.go:65 +0x129
Jan 24 19:53:09 BenNJ videominer[4170691]: github.com/cenkalti/backoff.RetryNotify(0xc0011e5f18, {0x8d23b8, 0xc0008a1860}, 0x0)
Jan 24 19:53:09 BenNJ videominer[4170691]:         /home/runner/go/pkg/mod/github.com/cenkalti/backoff@v2.2.1+incompatible/retry.go:37 +0x1ac
Jan 24 19:53:09 BenNJ videominer[4170691]: github.com/cenkalti/backoff.Retry(...)
Jan 24 19:53:09 BenNJ videominer[4170691]:         /home/runner/go/pkg/mod/github.com/cenkalti/backoff@v2.2.1+incompatible/retry.go:24
Jan 24 19:53:09 BenNJ videominer[4170691]: github.com/livepeer/go-livepeer/server.RunTranscoder(0xc000192180?, {0xc00013e068?, 0x21?}, 0xa?, {0xc00016d700?, 0xf?, 0x10?}, {0xe1, 0x3c, 0x31, ...})
Jan 24 19:53:09 BenNJ videominer[4170691]:         /home/runner/work/Videominer-Pool/Videominer-Pool/server/ot_rpc.go:63 +0x12a
Jan 24 19:53:09 BenNJ videominer[4170691]: created by github.com/livepeer/go-livepeer/cmd/livepeer/starter.StartLivepeer
Jan 24 19:53:09 BenNJ videominer[4170691]:         /home/runner/work/Videominer-Pool/Videominer-Pool/cmd/livepeer/starter/starter.go:1198 +0x6c38