reflog is git’s internal ‘last resort’ if you’ve lost a commit during a rebase (or something else equally scary).
If you run it on our workshop git repo, you should see the intermediate steps in the interactive rebase we did a few pages ago:
git reflog
4a91d30 (HEAD -> branch) HEAD@{0}: commit (amend): testing file
db94c2f HEAD@{1}: commit: testing file
ea54536 HEAD@{2}: rebase -i (finish): returning to refs/heads/branch
ea54536 HEAD@{3}: rebase -i (pick): rename to file
7b4f35b HEAD@{4}: rebase -i (pick): added important file
e58222c HEAD@{5}: rebase -i (squash): thirdcommit
c890001 HEAD@{6}: rebase -i (start): checkout HEAD~4
7c39e9e HEAD@{7}: rebase finished: returning to refs/heads/branch
7c39e9e HEAD@{8}: rebase: rename to file
5fd910b (master) HEAD@{9}: rebase: checkout master
335d198 HEAD@{10}: commit: rename to file
Say we wanted to get one of these back, or revert back to a state that isn’t screwed up - we just checkout that revision using it’s ref
git checkout 7c39e9e
It’ll warn you to the fact you’ve now have a DETACHED_HEAD ref
Note: checking out '7c39e9e'.
You are in 'detached HEAD' state. You can look around, make experimental changes and commit them, and you can discard any commits you make in this state without impacting any branches by performing another checkout.
To save this state, simply make a new branch, and then you can treat it as any other branch
git checkout -b undo-bad-thing
And then bam, you’ve got it back - magic!
Okay enough of logs, let’s make friends by blaming other people for commits.