Rails 4.0 compatibility

[florrain]

Hello,

I'm working with a Rails 4.0 application where I'm seeing this error. I'd like to upgrade the mysql2 client version to the latest as possible (0.4.6 and greater). The application is using a 0.3.x version currently.

I'm seeing two inconsistent versioning recommendations, one in the README and one in the 0.5.0 release notes.

mysql2 0.4.x works with Rails / Active Record 4.2.5 - 5.0 and higher.

For Rails 4.x please pin the gem to mysql2 '~> 0.4.0' to avoid the 0.5.x upgrade.

Could you tell which is the source of truth?

Thanks

[sodabrew]

Both statements are true.

[florrain]

The second infers that 4.0 and 4.2 can be used with ~> 0.4.0 which goes in conflict with the first that is stricter. I guess I'll go the safe way and try to do the Rails upgrade before mysql2.

[jcowhigjr]

https://stackoverflow.com/questions/22932282/gemloaderror-for-mysql2-gem-but-its-already-in-gemfile just in case someone is confused that the mysql2 gem can be added to the Gemfile with Rails 4.0, 4.1 etc .. You will see a failure when you boot the application. dbconsole might work but active record will complain: '...ensure its version is at the minimum required by ActiveRecord'

If someone sees this remember:

mysql2 0.4.x works with Rails / Active Record 4.2.5 - 5.0 and higher.