Question

I just ran git merge otherBranch and it output this error to the command line:

fatal: Failed to execute internal merge

What could this mean? I would give more details, but I’m not sure what details would be important. Have other people experienced this, and if so what caused it in your case?

EDIT:

It looks like this is a catch-all error message. However, if other people have found specific reasons for failure and think others might benefit from the solution you found, feel free to post those as well.

Answer 1

From the source of git:

        merge_status = merge_3way(o, &result_buf, one, a, b,
                      branch1, branch2);

        if ((merge_status < 0) || !result_buf.ptr)
            die("Failed to execute internal merge");

merge_3way is the function which (unsurprisingly) performs a three-way merge. So, the “failed to execute internal merge” message is printed any time the merge returns an error.

You almost certainly had another error message above the one you posted, which is the real cause.