corruption - How to resolve "Error: bad index – Fatal: index file corrupt" when using Git

Question

After git init, I added and committed a few files, made some changes, added and committed. Set up the git daemon (running under Cygwin on WinXP) and cloned the repository once. Now, I get this error with the cloned repository:

$ git status
error: bad index file sha1 signature
fatal: index file corrupt

Is there any way to fix this, other than getting a new copy of the repository?

Answer 1

If the problem is with the index as the staging area for commits (i.e. .git/index), you can simply remove the index (make a backup copy if you want), and then restore index to version in the last commit:

On OSX/Linux/Windows(With Git bash):

rm -f .git/index
git reset

On Windows (with CMD and not git bash):

del .gitindex
git reset

(The reset command above is the same as git reset --mixed HEAD)

You can alternatively use lower level plumbing git read-tree instead of git reset.

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If the problem is with index for packfile, you can recover it using git index-pack.