Older version of Ruby Parser Error



I’m trying to use an older version of Ruby but I keep getting a parser compatibility error

App 36588 stderr: warning: parser/current is loading parser/ruby22, which recognizes
App 36588 stderr: warning: 2.2.5-compliant syntax, but you are running 2.2.1.
App 36588 stderr: warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.

I managed to fix this by updating my ruby and rails versions but I actually really need to be using the older version as I am contributing to a larger project. Is there a way to fix this without updating?


You can switch to different Ruby versions in your workspace by using RVM (Ruby Version Manager). You can first list the current installed versions that RVM can use:

rvm list

Then you can choose one of those versions by running:

rvm use <version>

If the version you want to use is not installed then install it first, also using RVM:

rvm install <version>

And then switch to that version with the rvm use command.