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gitgit-am

What to do if git-am fails with “does not exist in index”?

I have a patch that gives out the following output when I try to apply it with git am

Checking patch old/filename...
error: old/filename: does not exist in index

Within the patch old/filename is actually moved to new/filename but it seems the original file is already missing from the source tree.

So what is the error about and how to solve / work-around it? Can it just be ignored (with --reject or so)?

Solution

  • The patch was not created against the correct source tree.

    One way this could happen:

    Assume your original branch (the one you want to apply the patch to) has commits:

    1. 1a -> 1b -> 1c -> 1d

    This branch is then cloned, and new commits are made:

    1. 1a -> 1b -> 1c -> 1d -> 1e

    Commit 1e included old/filename

    Now you do the work in the patch, based on the second branch, not the original one:

    1. 1a -> 1b -> 1c -> 1d -> 1e -> 1f

    Commit 1f included the rename old/filename -> new/filename

    Now, if you create a patch for commit 1f, you won't be able to apply it on top of commit 1d, because commit 1e is missing where old/filename was added to the index/repository.