PyTorch uses GitHub Actions for CI, so the rerun mechanism is as GHA defines it: Re-running workflows and jobs - GitHub Docs
Our pytorchbot has rules for certain exceptions if the failure looks irrelevant, and that information is usually displayed in our pytorchbot comment on every PR, e.g., POC for mixed prec optim frontend by janeyx99 · Pull Request #146640 · pytorch/pytorch · GitHub.
We’d advise erring on the side of caution in landing PRs, so we would recommend a rebase to get all green CI before merge instead of any sort of forced merging.