The reflog saves you

Goal#

Read the reflog, find commits no branch points at, and bring them back.

Git's diary#

Every time HEAD moves (a commit, a switch, a reset, a rebase), git writes a line in the reflog. It is local to your machine and kept for months: 90 days for most entries, and 30 for commits no branch can reach any more.

git reflog

In quest 11 it shows:

730017c HEAD@{0}: checkout: moving from secret-recipe to main
3a3f932 HEAD@{1}: commit: Write step 3
8ffd2e3 HEAD@{2}: commit: Write step 2
355a4c6 HEAD@{3}: commit: Write step 1
730017c HEAD@{4}: checkout: moving from main to secret-recipe
730017c HEAD@{5}: commit (initial): Start the recipe book

Read it from the bottom up: a branch was made, three steps were committed, then someone went back to main and deleted secret-recipe. The commits did not go anywhere. Only the label did.

Bring them back#

Put a new label on the lost commit:

git branch rescued 3a3f932

HEAD@{1} works too: it means "where HEAD was one move ago". Undoing a bad git reset --hard is the same move: find the line before the reset, and git reset --hard back to it.

Quest 11#

quest start 11

Someone deleted the secret-recipe branch with three commits on it. Find them in the reflog and put them on a branch called rescued. Then quest check.

Check it works#

• git log --oneline rescued shows all three recipe steps.
• quest check passes.

Exercise#

Make it harder on purpose: on rescued, run git reset --hard HEAD~2, so two steps vanish. Then use git reflog to undo your reset. Breathe easier next time you reset.

More to try

• git reflog show rescued shows one branch's own history.
• What can the reflog not save? Think about changes you never committed or stashed.