I am not part of the Rust team. I am part of Debian.
I am raining an issue generally in Debian, about a seemingly team-wide
behaviour that I find inappropriate for Debian.
I did not initially talk about build flags, but if others want to mix
that into the conversation, then fine with me. The conversation is then
the issue of how a seemingly team-wide behaviour fits into geneal Debian
ways of working.
Or, using "policy" words: I talk about Debian Policy, not some local
team-specific policy which I chose to exclude myself from when I, the
very first day that I joint said team, was told that policy dictated
that I*MUST* package every Rust library package in one giant git repo.
It was not optional or up for discussion, which made be leave that team.
So no, I am quite certainly not discussing Rust team policies here
(only, since you kinda ask for it, point fingers at them).
To get back to the topic of this conversation: DEB_BUILD_OPTIONS is a
quite common mechanism in Debian - not well supported by dh-cargo but
somewhat better by dh-rust.
I am suggesting to do what is common in Debian: Enable build flags for
optimization by default, and use DEB_BUILD_OPTIONS to disable where
needed.