Here's an example session: % LANG=C git fsck --strict; LANG=C git gc Checking object directories: 100% (256/256), done. error in tree 2699d230e3b592ae42506d7b5c969a7ac6a4593c: zeroPaddedFilemode: contains zero-padded file modes Checking objects: 100% (462555/462555), done. Verifying commits in commit graph: 100% (117904/117904), done. Enumerating objects: 462573, done. Counting objects: 100% (462573/462573), done. Delta compression using up to 8 threads Compressing objects: 100% (155363/155363), done. fatal: unable to read f5e44b38fc8f7e15e5e6718090d05b09912254fa fatal: failed to run repack % How come it can't read `f5e44b38fc8f7e15e5e6718090d05b09912254fa` during "repack" while `git fsck` says everything is fine? More importantly: how do I diagnose this further and fix it? Rumors on the net suggest that `git gc --aggressive` may circumvent this problem occasionally, but those don't seem to know what they're talking about, and in my case it didn't make any difference (except that it takes more time :-). Stefan