Hi,
Until now, my interest in corrupted repositories has been very
limited. Just now, the power went out for a second and my UPS failed
me. As a result, my ~/src/git is completely borked. For your
amusement, here's a quick session showing me bumbling around:
$ ~/src/git
error: object file
.git/objects/8e/6a6dda24b017915449897fcc1353a9b848fd2f is empty
error: object file
.git/objects/8e/6a6dda24b017915449897fcc1353a9b848fd2f is empty
fatal: loose object 8e6a6dda24b017915449897fcc1353a9b848fd2f (stored
in .git/objects/8e/6a6dda24b017915449897fcc1353a9b848fd2f) is corrupt
artagnon|remote-cruft*+:~/src/git$ rm
.git/objects/8e/6a6dda24b017915449897fcc1353a9b848fd2f
artagnon|remote-cruft*+:~/src/git$ git prune
artagnon|remote-cruft*+:~/src/git$ git status
fatal: bad object HEAD
fatal: bad object HEAD
artagnon|remote-cruft*+:~/src/git$ git symbolic-ref HEAD refs/heads/master
artagnon|master*+=:~/src/git$ git status
## master
MM Documentation/git-ls-remote.txt
MM remote.c
MM t/t5505-remote.sh
MM t/t5510-fetch.sh
MM t/t5515-fetch-merge-logic.sh
MM t/t5516-fetch-push.sh
?? lib/
?? outgoing/
That status is completely bogus, by the way.
artagnon|master*+=:~/src/git$ git reset --hard
artagnon|master*+=:~/src/git$ git checkout remote-cruft
fatal: reference is not a tree: remote-cruft
artagnon|master=:~/src/git$ git reflog
21ff915 HEAD@{10 minutes ago}: rebase -i (finish): returning to
refs/heads/remote-cruft
What happened to the rest of my reflog?! Okay, I give up. Let's go
back to what's present on Github. I push often, so it's not a
problem.
artagnon|master=:~/src/git$ git branch -D remote-cruft
error: Couldn't look up commit object for 'refs/heads/remote-cruft'
artagnon|master=:~/src/git$ rm .git/refs/heads/remote-cruft
artagnon|master=:~/src/git$ git checkout -b remote-cruft
Switched to a new branch 'remote-cruft'
Huh? What happened to my upstream?
artagnon|remote-cruft:~/src/git$ git branch -u ram/remote-cruft
warning: ignoring broken ref refs/remotes/ram/remote-cruft.
Fine, let's fetch.
artagnon|remote-cruft:~/src/git$ git fetch ram
remote: Counting objects: 101, done.
remote: Compressing objects: 100% (24/24), done.
remote: Total 92 (delta 78), reused 82 (delta 68)
error: object file
.git/objects/08/2b069c11e8d4f372b963b038cbf5b71a676ef6 is empty
fatal: loose object 082b069c11e8d4f372b963b038cbf5b71a676ef6 (stored
in .git/objects/08/2b069c11e8d4f372b963b038cbf5b71a676ef6) is corrupt
fatal: unpack-objects failed
Fine, let's run an fsck and get rid of all the corrupted objects.
$ git fsck
error: object file
.git/objects/08/2b069c11e8d4f372b963b038cbf5b71a676ef6 is empty
error: object file
.git/objects/08/2b069c11e8d4f372b963b038cbf5b71a676ef6 is empty
fatal: loose object 082b069c11e8d4f372b963b038cbf5b71a676ef6 (stored
in .git/objects/08/2b069c11e8d4f372b963b038cbf5b71a676ef6) is corrupt
artagnon|remote-cruft:~/src/git$ rm
.git/objects/08/2b069c11e8d4f372b963b038cbf5b71a676ef6
artagnon|remote-cruft:~/src/git$ git repack
artagnon|remote-cruft:~/src/git$ git fetch ram
remote: Counting objects: 101, done.
remote: Compressing objects: 100% (24/24), done.
remote: Total 92 (delta 78), reused 82 (delta 68)
Unpacking objects: 100% (92/92), done.
error: object file
.git/objects/64/fa33d706658278b871a6e2ca66694efcadacca is empty
fatal: loose object 64fa33d706658278b871a6e2ca66694efcadacca (stored
in .git/objects/64/fa33d706658278b871a6e2ca66694efcadacca) is corrupt
error: github.com:artagnon/git did not send all necessary objects
Fine, my packfiles are corrupt. Let's unpack-objects by hand.
artagnon|remote-cruft:~/src/git$ mv .git/objects/pack .git/objects/pack.old
artagnon|remote-cruft+:~/src/git$ for i in
.git/objects/pack.old/*.pack; do git unpack-objects -r <$i; done
artagnon|remote-cruft:~/src/git$ git fetch ram
remote: Counting objects: 101, done.
remote: Compressing objects: 100% (24/24), done.
remote: Total 92 (delta 78), reused 82 (delta 68)
Unpacking objects: 100% (92/92), done.
error: object file
.git/objects/64/fa33d706658278b871a6e2ca66694efcadacca is empty
fatal: loose object 64fa33d706658278b871a6e2ca66694efcadacca (stored
in .git/objects/64/fa33d706658278b871a6e2ca66694efcadacca) is corrupt
error: github.com:artagnon/git did not send all necessary objects
Auto packing the repository for optimum performance. You may also
run "git gc" manually. See "git help gc" for more information.
error: bad ref for refs/remotes/ram/remote-cruft
error: bad ref for refs/remotes/ram/remote-cruft
Counting objects: 161917, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (159963/159963), done.
Writing objects: 100% (161917/161917), done.
Total 161917 (delta 117725), reused 0 (delta 0)
Removing duplicate objects: 100% (256/256), done.
error: bad ref for refs/remotes/ram/remote-cruft
Checking connectivity: 161917, done.
warning: There are too many unreachable loose objects; run 'git
prune' to remove them.
I'm assuming it just went back and fetched everything the second time.
Why didn't it do that in the first place?
artagnon|remote-cruft:~/src/git$ git log ram/remote-cruft
warning: ignoring broken ref refs/remotes/ram/remote-cruft.
Now what? Why didn't the fetch update this ref?
artagnon|remote-cruft:~/src/git$ rm .git/refs/remotes/ram/remote-cruft
artagnon|remote-cruft:~/src/git$ git fetach ram
remote: Counting objects: 101, done.
remote: Compressing objects: 100% (24/24), done.
remote: Total 92 (delta 78), reused 82 (delta 68)
Unpacking objects: 100% (92/92), done.
From github.com:artagnon/git
* [new branch] remote-cruft -> ram/remote-cruft
* [new branch] upstream-fix -> ram/upstream-fix
Yes! Everything finally works.
Was I being stupid, or is fixing corrupted repositories really this
non-trivial? Comments appreciated.
Thanks.
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