Noisy warning from Parser (AutoInstrument)

[cschneid]

Seen on APM itself. When the parser library loads to do AutoInstruments, it warns if the patch version of Ruby doesn't match what it expects.

There are dozens of warnings like this emitted during a deploy.

The warnings don't seem to cause problems, just noise. It'd be nice to quiet them.

      01 warning: parser/current is loading parser/ruby24, which recognizes
      01 warning: 2.4.7-compliant syntax, but you are running 2.4.5.
      01 warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.

[ioquatix]

I wonder if we can do this upstream.

[jonekdahl]

The author of Parser has publicly stated that the warning is not going away. What you could do is offer instructions on how to make sure that you have a version of Parser that matches your Ruby version, which I believe involves upgrading either one or locking the versions to a known good combination (we're using ruby '2.6.5' and gem 'parser', '~> 2.6.5.0' in the Gemfile of our app).

[ioquatix]

@jonekdahl can you link us to this declaration?

[jonekdahl]

@ioquatix This is the comment I was thinking about: rubocop/rubocop#1819 (comment)

[dlanderson]

The solution here is to make sure the parser gem is set to the correct version for the version of ruby that's running. Another option is to use a gem which can be configured to ignore the warnings, like in this example:

# config/initializers/warning_ignores.rb

### https://github.com/jeremyevans/ruby-warning

Warning.ignore(/warning: parser/)