Can you elaborate? :)
We've got some pretty exciting changes coming up quite soon, but this isn't it.
I contribute to git.git, and it would be interesting to know if there's inherent issues stopping you from doing that, or if it's implementation problems in some cases (e.g. missing plumbing commands or features). There's definitely interest from upstream in reviewing patches / helping if there's missing or inadequate plumbing.
You'd get upstream features for free as they come along. E.g. presumably you haven't implemented the new MIDX format, but that speeds up pack file access by a lot for some use-cases, and presumably the boring bits of low-level git operations aren't much of a selling point in and of themselves.
Aside from whether you'd use "git" itself, such a trick of using a slave process you'd talk to over IPC of some sort would cover some of the issues you wrote about, e.g. issue with sharing global state with libraries like Breakpad.
In terms of getting the right data, one example is that we need to know the full set of non-ignored sub-directories in the working directory, so we can watch them for changes. It's easy enough to generate this ourselves as we calculate the status output, but I don't believe that git will emit it.
In terms of performance, we rely on being able to read objects efficiently. For example, to show a commit, we can't just use the output of "git diff", as we need the full file contents to be able to calculate syntax highlighting correctly. You could go a long way with "git cat-file --batch", but there are plenty of contexts where you can't practically batch requests, and process creation costs + the lack of caching across requests (which can be quite significantly due to the delta encoding of objects) would be quite significant.
Is there a way to make the "Staged Files" view appear at the top of the tool? Preferably above "Working Directory" ?
I'm trying out Sublime Merge, but it seems my git hooks aren't been called. Am I the only one experiencing this? A feature or a bug?
EDIT: Ok I found out it just takes the SSH key from ~/.ssh
But now it complains about C:\\Program Files\\Sublime Merge \\ssh-askpass-sublime.exe missing.