The approached I used was, I found few seniors who did GSOC from my university, and they have had great experience with the codebase and bug fixing. They were able to help me. Try contacting your seniors or past GSOC students of that organization. I agree there is a learning curve. When I tried the first time, it took me 3 weeks to setup the development environment. It was sheer will power back then. Let me know how it goes :)

PhD Candidate in Usable Privacy in Cyber-Physical Systems