In most cases I simply keep my fork as a PR and use the package either by vendoring or directly from the repo. If anyone else encounters the same bug, they will see my PR referencing the issue, they can do the same.
If many people are encountering the bug and using the package, and/or if the project seems dead, then it's a good idea to publish. You can do username prefix or you can just add "2" at the end. I've seen this for other repos, This is what https://crates.io/crates/zmq2 did while https://crates.io/crates/zmq was inactive, though the latter's maintainer became active and merged what the former's maintainer had done - you can see there is no animosity or anything.