What can I do with Git corruption due to a missing object?

Question

I just went to clone a repository on another remote server and ran into an issue trying to do so:

git clone [email protected]:blah/blah/docs.git
Cloning into docs...
remote: Counting objects: 343, done.
remote: error: unable to find 14f87a739828e4d489b0310a51e057b30333926e
remote: Compressing objects: 100% (325/325), done.
error: git upload-pack: git-pack-objects died with error.   
fatal: git upload-pack: aborting due to possible repository corruption on the remote side.
remote: fatal: unable to read 14f87a739828e4d489b0310a51e057b30333926e
remote: aborting due to possible repository corruption on the remote side.
fatal: early EOF
fatal: index-pack failed

I did a little research and found out about git fsck, here is the output:

$ git fsck --full
error: sha1 mismatch 14f87a739828e4d489b0310a51e057b30333926e

error: 14f87a739828e4d489b0310a51e057b30333926e: object corrupt or missing
missing blob 14f87a739828e4d489b0310a51e057b30333926e

All other people with similar problems have a broken link issue or something. I'm still fairly new with Git, does anyone know how to fix this?

I can still push to my central remote repository, but I can't clone it.

14f87a739828e4d489b0310a51e057b30333926e is a blob that is a markdown file in the repository root. I tried deleting this file and push those changes to no avail.

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Edit: Is it possible to import git history from a another repo? I'm thinking I could just start a new repo and copy my files into it and then import the commit history.

Answer 1

If it's only one single file and it's not packed yet, you should be able to find it in .git/objects/14/f87a739828e4d489b0310a51e057b30333926e in your local repository. You can copy this files to the corresponding directory in the repository on your server.

If it is packed, you should be able to unpack it using git unpack-objects on one of the pack files in .git/objects/pack/. After that, copying to the server works as described above.

Answer 2

Here is almost the same question with a very detailed solution: Github Repo Corruption - Sha1 Collision

Answer 3

Simple push will not fix this problem, because git sees it has the commit that refers to the corrupt file and will assume it has all the objects it needs.

Do you have another repository with the project that does not report any problems with fsck (and has the file in question)? E.g. on your local machine? Than you should try:

1. Put the corrupt repository aside.
2. Clone the good repository in it's place.
3. Push any branches the old repository had from other repositories or the old repository.

Since this kind of error means the file on disk was corrupt, I suggest you do a thorough check of the filesystem, the disk and also memory (the data could get corrupted in memory when git was saving them).

Note: While all disks have at least some checksums, most memory chips have none at all, so a memory fault is more likely to go undetected than a disk fault. memtest86+ is a good way to check memory.