Deterministic builds do more than merely defend against the Trusting Trust attack (what you and cperciva are dismissing as a flight of fancy equivalent to worrying about megabit-scale quantum computers in 2013) --- they also prevent compromised open-source binaries, a much more serious and realistic attack vector.

So we need to start implementing deterministic builds into every major open source project if we're even pretending like we care about putting up resistance to what's going on. If Tor browser can do it in just a few weekends, then so can we for mainstream Firefox, and hopefully eventually Ubuntu.