Each line represents one rebase in the format: [repo: PR_num : pre_commits: post_commits: local_pre_commits: local_post_commits: matched_indexes].
- pre_commits: an ordered list of commits in the first-parent of the head branch before rebasing.
- post_commits: an ordered list of commits in the first-parent of the head branch after rebasing.
- local_pre_commits: SHAs of pre_commits restored in our local machine.
- local_post_commits: SHAs of post_commits restored in our local machine.
The ordered list of commits is represented as [HEAD, ..., fork-point].