Build release binaries on Ubuntu 18.04

[lnicola]

Fixes #11558

[lnicola]

I don't know whether we really want to merge this. On one hand we generally don't work around old software versions, on the other hand it's a small change and seems to affect a good number of people.

r? @rust-analyzer/review

[SomeoneToIgnore]

Maybe add a comment/issue with some LTS expiration date to revisit and bump it later?

[lnicola]

We'll have to bump at the latest when GitHub discontinues those builders, so probably no need for that.

[lnicola]

I'll merge this tonight if there's no disagreement.

[lnicola]

bors r+

[bors]

Build succeeded:

• Rust (macos-latest)
• Rust (ubuntu-latest)
• Rust (windows-latest)
• TypeScript (ubuntu-latest)
• TypeScript (windows-latest)

[matklad]

I don't know whether we really want to merge this. On one hand we generally don't work around old software versions, on the other hand it's a small change and seems to affect a good number of people.

My personal heuristic here would be:

• Do support old stuff on best-effort basis if that's not to hard
• But be very explicit about this being just "best effort"

That is, the only problem here is that in the future, someone might ask for a more onerous change. Responding to that becomes much easier if you have a "precedent" PR which articulates the policy.

[lnicola]

Exactly, a similar thing came up in #10457 (comment).

[jonhoo]

Out of curiosity, will the rust-lang org adoption mean that rust-analyzer will be built and distributed entirely using the main Rust build infrastructure one day (maybe that's already what the nightly preview component does)? If so, that should help this a lot since we won't be at the mercy of when GitHub decides to drop support for old runners.

[matklad]

@jonhoo that's an open question at the moment! Using Rust distribution infra obviously brings a ton of benefits! But it comes with a sizable drawback -- a switch from 1 week release cycle to 6 weeks with additional 6 week lag.

[jonhoo]

All the more incentive for developers to use beta in the developer environments :p

[lnicola]

That still means losing the nightly versions of RA. We can't realistically upgrade merge the changes every day (it's a submodule update, not a "pull this repository, build it, then publish to the two marketplaces").

And our nightlies have been very useful in finding regressions.

[jonhoo]

True, though nothing precludes those builds from continuing to exist. The main Rust build would just provide a more stable release for those who are okay with not being on the bleeding edge if it gives them more dependable artifacts.

[lnicola]

maybe that's already what the nightly preview component does

That component has the latest stable (weekly) RA release, with a lag of a couple of days or so. There was a release yesterday, and I just filed a PR to update the submodule (rust-lang/rust#95424), which will probably get merged today or tomorrow.

We could update the submodule on Monday. I tend to wait a day just in case we find some critical regression, but that's probably not necessary.

So the rustup component basically "just" needs to be renamed and included in stable at some point.