如何找到用于特定Ruby版本或Rails版本的Gem版本

Question

I use multiple rails versions which coincides with ruby versions. For example:

server1:

• Rails 2.3.11
• Ruby 1.8.7p375

server2:

• Rails 3.2.18
• Ruby 2.2.10p489

For each of these scenarios, how can I determine which gem -v to use? Is there a list somewhere I can refer to?

Answer 1

If I understand your question properly, you're asking how you can determine which ruby version you can use for a specific rails version.

The ActiveRecord gemspec ( https://github.com/rails/rails/blob/3-0-stable/activerecord/activerecord.gemspec ) specifies a ruby constraint:

s.required_ruby_version = '>= 1.8.7'

You can also look at the .travis.yml file on the repo.

As an example, for rails 3.2: https://github.com/rails/rails/blob/3-2-stable/.travis.yml you'll see that they were running the whole test suite for all those ruby versions:

rvm:
  - 1.8.7
  - 1.9.2
  - 1.9.3
  - 2.0.0
  - 2.1.8
  - 2.2.6
  - 2.3.3

Which means that rails 3.2 should be compatible with any of those ruby versions.

Answer 2

https://rubygems.org/gems/rails/versions/5.2.1.rc1 Refer to the above link, if you are supposed to use rails version 5.2.1.rc1, then required ruby version will be atleast 2.2.2 and above. So from 2.2.2 to 2.5.1 ie latest version, any ruby version you can choose. Required ruby gems versions will be >= 1.8.11.