Padrino Project Generator Fails - Undefined Method `add_builtin_type'

Question

I'm new to both Ruby and Sinatra/Padrino so I apologize if I'm missing something really simple.

I have Sinatra working fine, as I can build a very simple "hello" app and see it work.

I wanted to move on and generate a new Padrino project, but when I do this:

$ padrino g project foobar

I get this:

/Users/dave/.rvm/gems/ruby-2.1.5/gems/activesupport-4.2.0/lib/active_support/ordered_hash.rb:3:in `<top (required)>': undefined method `add_builtin_type' for Psych:Module (NoMethodError)
from /Users/dave/.rvm/rubies/ruby-2.1.5/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:121:in `require'
from /Users/dave/.rvm/rubies/ruby-2.1.5/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:121:in `require'
from /Users/dave/.rvm/gems/ruby-2.1.5/gems/padrino-gen-0.12.4/lib/padrino-gen.rb:3:in `<top (required)>'
from /Users/dave/.rvm/rubies/ruby-2.1.5/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /Users/dave/.rvm/rubies/ruby-2.1.5/lib/ruby/site_ruby/2.1.0/rubygems/core_ext/kernel_require.rb:54:in `require'
from /Users/dave/.rvm/gems/ruby-2.1.5/gems/padrino-gen-0.12.4/bin/padrino-gen:12:in `<main>'

I have tried installing the Psych gem but this didn't change anything. I have no idea what to try next, or how to really interpret the error message. Any nudges in the right direction you can give me?

Answer 1

With me, after a lot of googling and reading various thread on S.O., it was only my rvm that was the problem. I was getting the rvm 'WARNING!' that rvm wasn't first in $PATH. You can check this with echo $PATH. Check out your ~/.bashrc see if there is anything like heroku toolbelt or linuxbrew, or whatever, loading themselves into your PATH at the FRONT i.e. PRE-PENDING your path, rather than APPENDING. This is indicated by something like export PATH="/usr/local/heroku/bin:$PATH". That sets heroku at the beginning of your PATH. Simply change it to export PATH="$PATH:/usr/local/heroku/bin".

I was trying to start a padrino project with activesupport, and this was causing problems. Changing to an earlier version of Ruby, as suggested in another thread, didn't cut it, because activesupport requires 2.2.0 or up.

Fixing my PATH, ensuring that rvm was initialized at the very beginning of the PATH, fixed my Padrino problem, and was able to initialize a project with the following command:

padrino g project sample_blog -t shoulda -e haml -c sass -s jquery -d activerecord -b

I know that's all a little off-tangent, but I think it's bound to help one or two people out there!

PS I'm using ruby 2.2.2p95 in this project folder.

Answer 2

I ran into this using rbenv and padrino 0.13.0. Tried many versions of Ruby, including the system Ruby on OS X El Capitan, but found that that made no difference, so I'm now running the latest stable one (2.2.4).

Eventually I tried each version of the psych gem and found I could only get padrino g to work with an older version of the gem. Psych version 2.0.8 worked, while every newer version (up to the current 2.0.16) failed.

So: gem install psych -v=2.0.8 && gem uninstall psych -v '>= 2.0.9'

Answer 3

I had this problem while using Ruby 2.1.5. After reading comments on here I realized it's not a RVM problem, but a ruby problem. I switched to 2.0.0-p576 and everything works. Psych must not be compatible with the new ruby versions.

However I don't understand how a different ruby version would cause this method to go missing. If anyone could explain that I would be grateful!

Answer 4

Bug reports show this may be an RVM issue.

I suggest changing from RVM to "ruby-install" and "chruby" because IMHO these are simpler, easier, and better at installing dependencies including psych and its libraries.

Answer 5

As joelparkerhenderson noted, the error message shows problems with gem files in the .rvm directory, suggesting some issue or conflict with rvm. Switching to system ruby solved the problem for me. I don't really need to use a specific version of ruby on this project, so that's a fine workaround for me.