It appears that this is just an easily misread bit of text - I was concerned from the readme that the job would just fail to be created, but the code strongly seems to indicate that the job simply won't get worked on if we are over the concurrency limit.
The readme specifies "a new job will not be scheduled if we are at or over a job's MaxConcurrency limit."
https://github.com/gocraft/work#job-concurrency
However the code implies the job will still be inserted, it just won't be selected or run.
https://github.com/gocraft/work/blob/5959e69ad211c5ca37ffdf3ede02e35a5ae41d98/redis.go#L107
It appears that this is just an easily misread bit of text - I was concerned from the readme that the job would just fail to be created, but the code strongly seems to indicate that the job simply won't get worked on if we are over the concurrency limit.