Support `Gemfile.lock` for `rubygems` input?

[haines]

It seems like the version numbers of RubyGems and Bundler are aligned now, in which case, would it make sense for the rubygems input to support Gemfile.lock as an option, so that you could get the same versions of RubyGems and Bundler installed based on the BUNDLED WITH version?

[eregon]

Is there a specific case where you need to update RubyGems?
I think it doesn't reflect usages in development, where users very rarely update RubyGems, so I think updating RubyGems should only be done when there is no other way, and to a fixed version.

[haines]

I was running into an issue (actually I think it's server-side, but I wanted to make sure it wasn't something that had been fixed client-side - rubygems/rubygems.org#6369).

I usually keep RubyGems up-to-date locally as well, but maybe I'm unusual 😅

It just seems like it makes sense to use matching versions of RubyGems and Bundle and now their versions are aligned, it's easy to infer from Gemfile.lock.

No worries if you don't think this would be generally useful, I have a workaround in place which does the job (haines/pg-aws_rds_iam@f36f0ae).

[eregon]

It just seems like it makes sense to use matching versions of RubyGems and Bundle and now their versions are aligned, it's easy to infer from Gemfile.lock.

Mmh, maybe. What makes this weird is it used to not be the case, so this is rather brittle.
Also there is likely some extra complications given that recent RubyGems versions are incompatible with older Ruby versions, yet maybe recent Bundler might install there (unless RubyGems & Bundler required_ruby_version align?)?

In development I don't know of any tool that e.g. would update RubyGems based on the BUNDLED WITH section in Gemfile.lock, so that's the disconnect here. Also in general it doesn't make much sense to downgrade RubyGems, but with this it could either happen or be ignored, which is more variability.
I think for CI stability reasons it's best to no have this option.

[haines]

Ok, no problem, thanks for considering it!