In August, every student needs to make an upload of code to Google.
This is a mandatory requirement to pass GSoC.
In the case of my students, it is easy to track all their work because they
have worked on separate repositories (created just for GSoC), and 99%
of the latest commits there are from them (with a few commits from the mentors).
For example, for the EasyGnuPG project, one can track all the commits
from this simple link:
Another link that is very useful for tracking the history of the work is this
one:
Besides all the issues, it also shows all the pull requests from this
author (it turns out that pull requests in GitHub are just a special kind
of issues). Being able to track pull requests is very useful because they
also include comments and discussions about the code (between student
and mentors).