Add Ruby 3.1 compability

[spickermann]

Ruby 3.1.0 was released on Christmas.

Today I started updating our apps and noticed that google-protobuf is not compatible with Ruby 3.1 yet.

google-protobuf-3.19.1-x86_64-darwin requires ruby version < 3.1.dev, >= 2.3, which is incompatible with 
the current version, ruby 3.1.0p0

I understand that it might take some time to get this fixes – especially during the end of year break. I created this issue to keep track of this and me notified when a updated version was released.

Cheers and Happy New Year.

[brauliobo]

same here, what is holding this?

[perezd]

Has anyone tried upgrading this to see what the breakages are? We're accepting PRs.

[arathunku]

We've been running an updated version in ~medium size app for the last few weeks, no new errors.

[perezd]

@arathunku, would you be comfortable sending a PR to allow Ruby 3.1 to be acceptable? We're not immediately sure where this limitation is coming from.

[jchestershopify]

As another data point, we are seeing this problem across multiple apps, affecting google-protobuf up to and including v3.19.4.

[haberman]

It's unclear to me why our gem is not compatible with Ruby 3.1.

Our gemspec's required_ruby_version is >=2.3:

protobuf/ruby/google-protobuf.gemspec

Line 25 in 020e4e3

s.required_ruby_version = '>= 2.3'

There is nothing from our end that should be prohibiting 3.1.

[Maaarcocr]

It's unclear to me why our gem is not compatible with Ruby 3.1.

Our gemspec's required_ruby_version is >=2.3:

protobuf/ruby/google-protobuf.gemspec

Line 25 in 020e4e3

s.required_ruby_version = '>= 2.3'

There is nothing from our end that should be prohibiting 3.1.

The issue is that the pre-compiled versions of the gem do not support 3.1 as per

protobuf/ruby/Rakefile

Line 128 in 1d13b60

IN_DOCKER=true rake native:#{plat} pkg/#{spec.full_name}-#{plat}.gem RUBY_CC_VERSION=3.0.0:2.7.0:2.6.0:2.5.0

I made a PR to fix it here: #9566