Fixing "uninitialized constant ActiveSupport::Dependencies::Mutex (NameError)"

If you get a stacktrace complaining about uninitialized constant MysqlCompat::MysqlRes a system library update might broke your gem.

You might have [switched from MySQL to MariaDB](https://makandracards.com/makandra/51171-running-rails-2-apps-w...

Phillip Koebbe from Ruby on Rails suggested inserting following code between the "bootstrap" and "initialize" sections of enviroment.rb. This hack fixes the problem.

if Gem::VERSION >= "1.3.6"
  module Rails
    class GemDependency

...

There is a conflict between current capistrano versions and the 2.5.1 net-ssh gem. Make sure you upgrade to 2.5.2, then it should work again.

Example:

  class Book::Page
  end
  
  class MyBook < Book
    def new_page
      Page.new # has to be `Book::Page` in development to make it work 
    end
  end

Method new_page may throw an error when it was called during browser inte...

These warnings are printed when the etc Gem is installed, while etc is also included in Ruby. Fix with:

gem uninstall etc

If you want to access top-level constants inside a BasicObject class, you need to prefix them with ::.

This will not work

class Foo < BasicObject
  def bar
    Hash.new
  end
end

Foo.new.bar # => NameError: uninitialized constant Foo::Has...

Use bundler > 1.15 to fix Gem::LOADED_SPECS_MUTEX (NameError).

Given the following project:

ruby -v
ruby 1.8.7

bundler -v
Bundler version 1.13.7

gem -v
1.8.30

rails -v
Rails 3.2.22.1

Running specs or features resulted in:

`...

When defining a trait using the Modularity gem, you must take extra steps to define constants to avoid caveats (like when defining subclasses through traits).

[...