Library not loaded error — wrong ruby

Question

I'm using RVM with Ruby 1.9.3 p448, but when I try to run my rails server, I get this error (plus some other stuff)

9): Library not loaded: /Users/sashafklein/.rvm/rubies/ruby-1.9.3-p327/lib/libruby.1.9.1.dylib (LoadError)
      Referenced from: /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix_spawn_ext.bundle
      Reason: image not found - /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix_spawn_ext.bundle

The weird thing is, it's referencing ruby-1.9.3-p327, which isn't even one of my RVM installs. Should I delete that Ruby folder it's not finding libruby in? Or what else might be wrong?

EDIT -- Full Error

/Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require': dlopen(/Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix_spawn_ext.bundle, 9): Library not loaded: /Users/sashafklein/.rvm/rubies/ruby-1.9.3-p327/lib/libruby.1.9.1.dylib (LoadError)
  Referenced from: /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix_spawn_ext.bundle
  Reason: image not found - /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix_spawn_ext.bundle
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix/spawn.rb:2:in `<top (required)>'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix-spawn.rb:1:in `<top (required)>'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `block in require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:236:in `load_dependency'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/activesupport-3.2.13/lib/active_support/dependencies.rb:251:in `require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/albino-1.3.3/lib/albino.rb:1:in `<top (required)>'
  from /Users/sashafklein/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `require'
  from /Users/sashafklein/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/lib/bundler/runtime.rb:72:in `block (2 levels) in require'
  from /Users/sashafklein/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `each'
  from /Users/sashafklein/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/lib/bundler/runtime.rb:70:in `block in require'
  from /Users/sashafklein/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `each'
  from /Users/sashafklein/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/lib/bundler/runtime.rb:59:in `require'
  from /Users/sashafklein/.rvm/gems/ruby-1.9.3-p448/gems/bundler-1.3.5/lib/bundler.rb:132:in `require'
  from /Users/sashafklein/rails/<appname>/config/application.rb:12:in `<top (required)>'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:53:in `require'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:53:in `block in <top (required)>'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:50:in `tap'
  from /Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/railties-3.2.13/lib/rails/commands.rb:50:in `<top (required)>'
  from script/rails:6:in `require'
  from script/rails:6:in `<main>'

The albino gem seems to be at the bottom of this, but I think it's necessary for the app, so I can't just take it out. I tried gem uninstall albino (which gave no output) and then bundle install, but that didn't fix anything. Likewise with bundle update, and likewise with mpapis's and sahil's help below.

Answer 1

this kind of thing could happen when gems are linked wrong, try this:

rvm get head
rvm reinstall 1.9.3-p448
rvm use 1.9.3-p448

This will reinstall the ruby and make all gems pristine, which should prevent such problems from happening - unless gem authors did some extra tricks which go out of standard ruby detection.

Update

Using bundlers flag --deployment or --path is not always safe, the error message says:

/Users/sashafklein/rails/<appname>/vendor/bundle/ruby/1.9.1/gems/posix-spawn-0.3.6/lib/posix_spawn_ext.bundle

Which means the gem was compiled with the other ruby and now can not find it.

The simplest way to fix it is to stop using --deployment flag, as it is persisted the easiest way to get rid of it (and all other potentially dangerous settings) is:

rm -rf .bundle/ vendor/bundle 
bundle install

Interpretation

Bundler does great job filtering gems in runtime, unfortunately it enforces another layer of filtering with the --deployment flag, which forces installation of gems to path that is common for multiple rubies - in this case: ruby/1.9.1, this is unsafe as rubies can be compiled with different settings which can break c-extension gems used in different ruby.