git-fsck

Check repository integrity

$ git fsck

$ git fsck --unreachable

$ git fsck --full

$ git fsck [object]

$ git fsck --dangling

$ git fsck --connectivity-only

git fsck [options] [objects...]

git fsck (file system check) performs integrity verification on all objects in the Git object database. It validates that objects are well-formed, correctly connected, and that the repository structure is consistent and uncorrupted.
The command checks for corrupted objects, broken links, invalid object types, and unreachable objects that exist but are not referenced by any branch or tag. Unreachable objects are often the result of rebases, amended commits, or deleted branches, and can be useful for recovering accidentally deleted work via the --lost-found option.
Regular fsck runs are recommended after suspected repository corruption, disk errors, or hardware failures. The --full option extends checking to objects inside pack files rather than just checking pack file integrity.

--unreachable

Show unreachable objects.

Show dangling objects.

Check objects in packs.

Check connectivity only.

Enable strict checking.

Write dangling objects to .git/lost-found.

git-gc(1), git-prune(1)