Consider requiring a super-majority, not just a majority, to reach FCP

[scottmcm]

In the @rust-lang/lang meeting today were discussed that it feels odd for our p-FCPs to reach FCP with just 3/5 checkboxes.

I would propose that the rule change to "⅔ supermajority and at most N remaining" -- for a team of 4 this would still require 3/4, but for a team of 5 it would require 4/5 instead of the current 3/5. 4/6 would be unchanged for a 6-member team.

[nikomatsakis]

Supermajority here is 75%?

[scottmcm]

Oh, good point -- I don't know why I had it in my head that it was always ⅔. I updated my post above, but don't have a particularly strong reasoning available for why it should be ⅔ instead of ¾ or 1/ϕ or whatever.

[RalfJung]

With @rust-lang/opsem also having only 5 members, I agree -- I feel like we should wait for at least 4/5 to approve before going into FCP.

[RalfJung]

So... can someone just make a PR that adjusts this line?

rfcbot-rs/src/github/nag.rs

Line 398 in 365810a

let majority_complete = num_outstanding_reviews < num_complete_reviews;

Maybe to something like this?

// Require a 2/3 supermajority (where exactly 2/3 are sufficient)
let majority_complete = num_outstanding_reviews*2 <= num_complete_reviews;

We can change the 2 to a 3 for a 3/4 supermajority. I changed < to <= since I assumed exactly 2/3 of team members should be considered accepted.

This touches the core of our decision making process and I have no idea what the process is for doing that.^^

[JakobDegen]

Oh, I'm realizing that the comments from lang team members are two years old and so may be outdated. Anyway, I've nominated for discussion by the council here , I'm sure people can leave feedback in that thread or the council will otherwise find a way to make sure this has wide support

[scottmcm]

I'm still a fan of the ≥⅔ that Ralf is proposing, FWIW.

[joshtriplett]

Likewise.

[RalfJung]

My attempt to change this in rust-lang/rust#114986 got blocked on the concern that other teams that currently have less than 5 or more than 5 members might have 5 members in the future, and if we changed the rules for 5-member teams now then those teams might accidentally fail to reach consensus despite the team thinking they should have consensus.

So, doesn't look like we'll get to have our desired consensus rules any time soon. Bummer.

Implementation-wise I assume this is now blocked on #319.