[Full Changelog](https://github.com/nodegit/nodegit/compare/v0.25.0-alpha.8...v0.25.0-alpha.9)

- Removed access to the diff_so_far param in git_diff_notify_cb and git_diff_progress_cb

- Changed FilterSource.prototype.repo to async to prevent segfaults on filters that run during Submodule.status

- Clean up deprecation messages to inform users of what was deprecated, not just what users should switch to

- When installing on a machine that has yarn and does not have npm, the preinstall script should succeed now

- ceiling_dirs is now an optional parameter to Repository.discover

- [Clean up some dangerous memory accesses in callbacks #1642](https://github.com/nodegit/nodegit/pull/1642)

- [Output the item that was deprecated when giving deprecation notice #1643](https://github.com/nodegit/nodegit/pull/1643)

- [Don't fail yarn installs when we can't find npm #1644](https://github.com/nodegit/nodegit/pull/1644)

- [`ceiling_dirs` parameter in `Repository.discover` is optional #1245](https://github.com/nodegit/nodegit/pull/1245)