rails: Rails 4.2.11.2: uninitialized constant Module::DELEGATION_RESERVED_METHOD_NAMES

I am very sorry. I will make a release again.

I shipped 4.2.11.3 with #39302. Thanks for reporting this as well as the PR to fix it.

Thanks, @tenderlove!

Please note that Rails 4.2 is not supported. We are trying to do a favor to people still using that unsupported version by releasing a new version instead of just sending an advisory with a patch. The Rails 4.2 build is not passing anymore given the Ruby versions supported today are different of the versions supported on that series, so we can’t expect the build will pass when we make a security release. That is how this passed through review and automated testing to make in to an unsupported official release.

I have a PR up for this in #39302.

I’m curious to know how this passed through review and automated testing to make it to an official release.

This commit https://github.com/rails/rails/commit/4c46a15e0a7815ca9e4cd7c7fda042eb8c1b7724 broke redmine 3.4 (/my/page):

--- rails-4.2.11.1/actionview/lib/action_view/template.rb       2019-03-11 21:21:15.000000000 +0300
+++ rails-4.2.11.3/actionview/lib/action_view/template.rb       2020-05-15 21:34:31.000000000 +0300
@@ -312,8 +312,12 @@
       end
 
       def locals_code #:nodoc:
+        # Only locals with valid variable names get set directly. Others will
+        # still be available in local_assigns.
+        locals = @locals.to_set - Module::DELEGATION_RESERVED_METHOD_NAMES
+        locals = locals.grep(/\A(?![A-Z0-9])(?:[[:alnum:]_]|[^\0-\177])+\z/)
         # Double assign to suppress the dreaded 'assigned but unused variable' warning
-        @locals.each_with_object('') { |key, code| code << "#{key} = #{key} = local_assigns[:#{key}];" }
+        locals.each_with_object('') { |key, code| code << "#{key} = #{key} = local_assigns[:#{key}];" }
       end
 
       def method_name #:nodoc:

production.log:

Started GET "/my/page" for IP at 2020-06-01 14:51:53 +0300
Processing by MyController#page as HTML
  Current user: VVD (id=XXXX)
  Rendered my/blocks/_issues.erb (37.8ms)
  Rendered my/page.html.erb within layouts/base (5375.3ms)
Completed 500 Internal Server Error in 5490ms (ActiveRecord: 541.4ms)

ActionView::Template::Error (undefined local variable or method `block' for #<#<Class:0x0000000817a16200>:0x0000000817a2e300>):
    1: <div class="contextual">
    2:   <%= link_to_function l(:label_options), "$('##{block}-settings').toggle();", :class => 'icon-only icon-settings', :titl
e => l(:label_options) %>
    3: </div>
    4: 
    5: <h3>
  app/views/my/blocks/_issues.erb:2:in `_app_views_my_blocks__issues_erb___1895067040708881672_17382521500'
  app/helpers/my_helper.rb:103:in `render_issuesassignedtome_block'
  app/helpers/my_helper.rb:64:in `render_block_content'
  app/helpers/my_helper.rb:35:in `render_block'
  app/helpers/my_helper.rb:27:in `block in render_blocks'
  app/helpers/my_helper.rb:26:in `each'
  app/helpers/my_helper.rb:26:in `render_blocks'
  app/views/my/page.html.erb:13:in `block in _app_views_my_page_html_erb__4123894328546915933_17378179780'
  app/views/my/page.html.erb:11:in `each'
  app/views/my/page.html.erb:11:in `_app_views_my_page_html_erb__4123894328546915933_17378179780'
  lib/redmine/sudo_mode.rb:63:in `sudo_mode'
  plugins/redmine_dmsf/lib/redmine_dmsf/webdav/custom_middleware.rb:68:in `call'

After manual revert this patch error gone.

As someone who is currently running Rails 4.2 + Ruby 2.4 I’d be happy to help get the build green again. I would just need some pointers in the right direction.

Thank you for the offer but Rails 4.2 is not supported anymore and even just reviewing changes to the test suite would still require time and energy from the core team on a version that is not supported.