How do I resolve a git-svn index mismatch?

When I did a git svn rebase it stopped at one point saying:

Index mismatch: SHA key of a tree != SHA key of another tree. (I come to know that these SHA keys corresponds to a tree and not a commit from git show of the above two sha keys.)

re-reading <sha index of a commit in svn/trunk>
... list of files ...
fatal: bad object <SHA1 index of the bad object>
rev-list -1 <SHA1 index of the bad object> --not <SHA1 index of the revision it was trying to re-read>: command returned error: 128

I am not very experienced in the internal workings of git, so is there a sequence of steps to follow to dissect problems like these and possibly resolve them?

Solution

I've had this error twice and both times resolved it by removing the svn folder inside the .git folder.

rm -r .git/svn

then rebuild the svn metadata with:

git svn fetch

You will probably see a message along the lines of:

Migrating from a git-svn v1 layout...
Data from a previous version of git-svn exists, but
    .git/svn
    (required for this version (1.7.0.4) of git-svn) does not exist.
Done migrating from a git-svn v1 layout

and after while (rebuilding can take a while especially on large repositories) you should end up with a working mirror of the svn repository again.