A subtlety that may be lost: FreeBSD uses CVS, and so there isn't a way to commit locally while you're working, like with a DVCS.

FreeBSD hasn't used CVS since 2008.

Huh! So, before I posted this, I went to go double check, and found https://wiki.freebsd.org/VersionControl. What I missed was the (now obvious) banner saying

> The sections below are currently a historical reference covering FreeBSD's migration from CVS to Subversion.

My apologies! At the end of the day, the point still stands in that SVN isn't a DVCS and so you wouldn't want to be committing unfinished code though, correct?

(I suspect I got FreeBSD mixed up with OpenBSD in my head here, embarrassing.)

You could still use git-svn, but yeah, as another commenter wrote, I don't think reproducible build is that useful when debugging, it should be fine to have an actual timestamp in the binaries.

Well yes, but we've actually migrated to Git now. ;-)

Welp! Egg on my face twice!

It's in the FreeBSD src tree. But we usually commit code once it's working...

Huh. If I was confident enough in a change to consider it worth doing an actual boot to test I'd certainly want to have it committed, to be able to track and go back to it. Even the broken parts of history are valuable IME.