uninitialized constant ActionView::Template::Handlers::ERB::Erubi (NameError)

[wyattisimo]

I'm getting "uninitialized constant ActionView::Template::Handlers::ERB::Erubi (NameError)" on line 37 of haml/lib/haml/railtie.rb:

haml/lib/haml/railtie.rb

Lines 36 to 37 in c1b38ed

	if defined?(::Erubi) && const_defined?('ActionView::Template::Handlers::ERB::Erubi') &&
	ActionView::Template::Handlers::ERB::Erubi != ::Erubi

Dumping some context...

const_defined?('::Erubi') #=> true

defined?(::Erubi) #=> constant

const_defined?('ActionView::Template::Handlers::ERB::Erubi') #=> true

defined?(ActionView::Template::Handlers::ERB::Erubi) #=> nil

I'm using MRI v2.6.3 and Rails v4.2.11.1. Any clue what's going on here? Why would const_defined? say a constant by that name exists, but defined? doesn't recognize it? Is there possibly a scoping issue?

[nickhammond]

@wyattisimo Some useful context around Erubi in #946, similar issue.

[amatsuda]

Thank you for reporting this!

This seems like a ruby's bug to me. https://bugs.ruby-lang.org/issues/15875
But for now we need a fix in Haml's side not to hit this const_defined? bug.

[amatsuda]

So, this used to be happening only when you're using rails 4.2.x with haml 5.1.0, and bundling erubi or something that depends on erubi (e.g. better_errors), and running them on ruby 2.6.1-2.6.3.

Now it's been fixed via 9374849 and 09cb8ef, hopefully.

[amatsuda]

This has to be fixed in 5.1.1 release https://rubygems.org/gems/haml/versions/5.1.1
Please let us know if you're still seeing this problem with 5.1.1 or newer.