Modify about:buildconfig to include reproducible build information
While reading the Hacking doc, I saw the following:
Be aware that this process is not fully future-proof. In particular, if Debian has updated their development tool chain since the bundles have been built, you may encounter differences between your resulting bundles and the original binaries. This should be rare, however, as we use only the "Long Term Support" or "Oldstable" of Debian in our build VMs. The only reason they should change the tool chain is in the event of serious security issues in the development tools themselves.
It seems like it would be advantageous to include a bunch of (additional) information in about:buildconfig to allow fully reproducing (or at least comparing) builds, such as git tags/commits and information about reproducible build environment, such as the versions of packages.