git-lost-found (1) - Linux Manuals
git-lost-found: Recover lost refs that luckily have not yet been pruned
git-lost-found - Recover lost refs that luckily have not yet been pruned
NOTE: this command is deprecated. Use git-fsck(1) with the option --lost-found instead.
Finds dangling commits and tags from the object database, and creates refs to them in the .git/lost-found/ directory. Commits and tags that dereference to commits are stored in .git/lost-found/commit, and other objects are stored in .git/lost-found/other.
Suppose you run git tag -f and mistype the tag to overwrite. The ref to your tag is overwritten, but until you run git prune, the tag itself is still there.
$ git lost-found [1ef2b196d909eed523d4f3c9bf54b78cdd6843c6] GIT 0.99.9c ...
Also you can use gitk to browse how any tags found relate to each other.
$ gitk $(cd .git/lost-found/commit && echo ??*)
After making sure you know which the object is the tag you are looking for, you can reconnect it to your regular refs hierarchy by using the update-ref command.
$ git cat-file -t 1ef2b196 tag $ git cat-file tag 1ef2b196 object fa41bbce8e38c67a218415de6cfa510c7e50032a type commit tag v0.99.9c tagger Junio C Hamano <junkio [at] cox.net> 1131059594 -0800 GIT 0.99.9c This contains the following changes from the "master" branch, since ... $ git update-ref refs/tags/not-lost-anymore 1ef2b196 $ git rev-parse not-lost-anymore 1ef2b196d909eed523d4f3c9bf54b78cdd6843c6
Part of the git(1) suite