Bundler and wrong binstubs? - ruby

Question

I run rails s or bundle exec rails s and I get this warning:
Bundler is using a binstub that was created for a different gem.
This is deprecated, in future versions you may need to `bundle binstub rails` to work around a system/bundle conflict.
What does this mean? From looking around the bundler site, my understanding of binstubs is that you can set executables to them, so instead of running bundle exec blabla you can just do bin/blabla. So this error is saying my bundler isn't set to the right binstub?
When I run the bundle binstub rails I get this output
rails has no executables, but you may want one from a gem it depends on.
railties has: rails
bundler has: bundle, bundler
I do not understand what my system is trying to tell me, and it's not breaking anything, but I have a hunch this could turn into a bigger issue if I don't fix it
ruby 2.0.0p247
which ruby
/Users/evan/.rvm/rubies/ruby-2.0.0-p247/bin/ruby
which bundler
/Users/evan/.rvm/gems/ruby-2.0.0-p247/bin/bundler
Rails 4.0.2
Edit:
So, if I run the commands in the nag message:
bundle config --delete bin # Turn off Bundler's stub generator
rake rails:update:bin # Use the new Rails 4 executables
I end up getting uninitialized constant Bundler errors with bundle exec commands and the only way I've found to fix that is to rerun bundle install --binstubs which brings back the nag message at the start of this post.

Answer 1

What worked for me was
rm -rf bin/*
Then open a new terminal session and
bundle exec rake app:update:bin

Answer 2

Solution in my case: - Other solutions didn't work for me.
In your Rails directory:
mv /usr/bin/rails /usr/bin/rails.old
bundle config --delete bin
rm -rf bin
# for rails 4.x:
rake rails:update:bin
# for rails 3.x:
bundle install --binstubs
# if you're using rbenv
rbenv rehash
rm -rf ~/.rbenv/plugins/{rbenv-bundle-exec,rbenv-gemset,bundler}
Also be sure that bin/rails is added to the path like:
PATH=./bin:$PATH
Good luck.

Answer 3

This error may raise when you update your ruby but not the related gems.
To check if this is your case, try to make a new rails app in a new empty directory (to be sure RVM is not autoloading any gemset)
make /tmp/test && cd test && rails new test
If this fails stating that it cannot find a suitable 'rails', then simply run
gem update
and overwrite any conflicting rails.

Answer 4

gem uninstall bundler
gem install bundler
Uninstalling all my versions of Bundler, and then installing the latest version fixed it for me. I had multiple versions of bundler installed, so when I ran bundle exec rails s I think the wrong Bundler was used, giving me the warning message.
You may need to generate new stubs after reinstalling Bundler, but I didn't have to.

Answer 5

I was able to fix this by looking at the commit history for bin/rails using git log -p bin/rails
The current, error producing content is:
#!/usr/bin/env ruby
#
# This file was generated by Bundler.
#
# The application 'rails' is installed as part of a gem, and
# this file is here to facilitate running it.
#
require 'pathname'
ENV['BUNDLE_GEMFILE'] ||= File.expand_path("../../Gemfile",
Pathname.new(__FILE__).realpath)
require 'rubygems'
require 'bundler/setup'
load Gem.bin_path('railties', 'rails')
The original, non-error content was:
#!/usr/bin/env ruby
APP_PATH = File.expand_path('../../config/application', __FILE__)
require_relative '../config/boot'
require 'rails/commands'
When I restored the original bin/rails content, the warning message disappeared. Previous attempts had returned uninitialized constant Bundler errors on all bundle exec commands, but now they work. It's worth noting that the original content appears to be exactly what rails new blabla generates in rails 4.0.x.
Still, I would like to know why the first code block causes issues because it's exactly what bundle install --binstubs generates.
Edit: turns out this solution does not work. Pushed this fix to a heroku staging server and heroku errors on startup: all bin/rails commands throw uninitialized constant Bundler and heroku starts up with bin/rails server ..... so this is a not really a fix.
Edit2:
If I add these two lines to the second block (the original bin/rails content), all bin/rails commands are working again:
require 'rubygems'
require 'bundler/setup'
My guess is that the second line is what fixes the bundler errors I was having.
Interestingly, when I tried to edit the first block of code in this post to try and debug which line was throwing the warning, any change I made caused all rails commands to failure, with no information except for the nag note in the OP. weird.
Final bin/rails that fixed my issue:
#!/usr/bin/env ruby
APP_PATH = File.expand_path('../../config/application', __FILE__)
require_relative '../config/boot'
require 'rubygems'
require 'bundler/setup'
require 'rails/commands'
Any additional insight from people who find this would be welcome!