BuildBot Repository Base

When i download a core from buildbot, where i can know the source repository from wich the core has been compiled.

Example : Is the blastem core compiled from old repository (outdated) https://github.com/libretro/blastem-libretro Or directly from the official repository (stable branch) https://www.retrodev.com/repos/blastem/shortlog/default

Thank for you information, i have difficulties to understand exactly what I download.