bbobb, tha_watcha, and Jaben are the only developers who have access to the 'master' source branch. It's been that way for several years now. When I run builds on my Visual Studio it takes all of about 2 minutes to build the entire solution and test --
Anytime I have enhancements, I actually post the code here on the forums and let them include it if they are going to -- then it appears in a day or so in my SVN and it's added.
While the application is open source, it is pretty tied down with who has direct access to adding to the source packages. I think a small part of that is that YAF does have offerings for commercial clients, and as such - any code changes have to go through testing purposes with Jaben (and bbobb as he is the SQL master here) - between them, they perform most of the code testing initially before adding to GIT - then it goes through the Alpha/Beta/RC process as most other apps do normally.
I don't know about GIT bit with Tortoise, there are files I set that are not to be compared against the master (such as the SLN and CSPROJ files) - then Tortoise doesn't complain when I make changes.
As an example, when I do my work, I have my local repository, and I have a development tree outside of that. Any changes I make I do to my dev tree. When they successfully compile and run, I'll submit changes to either the forum or submit a pull request with the changed files -- and then they will appear (if used) in my SVN later on. This keeps my 'local development' untangled from the repository while still allowing me access to everything. I understand how this can make more work - but in the end, I believe much of it is done to protect the integrity of the source code.
Jaben, tha_watcha, and bbobb may further clarify or have more solutions than I do. I'm not a part of the development team directly - I'm in the support area <grin> - but I do from time to time post patches to help them out where I can --
If you're looking to join the dev team directly, you'll have to get with Jaben as he's the current (and longtime) project leader - he's the only one who can add more devs to the team that I know of, and I don't know what his rules are for taking on more devs. I know he's definitely open to the discussion - just that he's beyond busy lately.
Hope this helps, and if there's more I can do - let me know --
If you can't find it using the forum search, try my signature link -- searches this site using Google: Google is my Friend