铁路新 <app> 或rails -h craps out with无法加载此类文件 - io / console

Question

[ec2-user@ip-XX-XXX-XXX-XXX rails]$ rails -h
/usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- io/console (LoadError)
    from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/shell/basic.rb:2:in `<top (required)>'
    from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/shell/color.rb:1:in `<top (required)>'
    from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/shell.rb:17:in `shell'
    from /usr/local/share/ruby/gems/2.0/gems/thor-0.19.1/lib/thor/base.rb:439:in `start'
    from /usr/local/share/ruby/gems/2.0/gems/railties-4.1.0/lib/rails/commands/application.rb:17:in `<top (required)>'
    from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/local/share/ruby/gems/2.0/gems/railties-4.1.0/lib/rails/cli.rb:14:in `<top (required)>'
    from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/share/ruby/vendor_ruby/2.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/local/share/ruby/gems/2.0/gems/railties-4.1.0/bin/rails:9:in `<top (required)>'
    from /usr/local/bin/rails:23:in `load'
    from /usr/local/bin/rails:23:in `<main>'

I did install Ruby on Rails using $ gem install rails and it completed fine as well. I had checked the process status with $echo $? and it was 0 meaning successful.

Interestingly these two commands work fine:

$ which rails
/usr/local/bin/rails

$ rails -v
Rails 4.1.0

This is a Amazon Web Services AMI image 64 bit. Please help me figure this out.

I have the bundler installed:

$ gem install bundler
Fetching: bundler-1.6.2.gem (100%)
Successfully installed bundler-1.6.2
Parsing documentation for bundler-1.6.2
Installing ri documentation for bundler-1.6.2
Done installing documentation for bundler after 5 seconds
1 gem installed

I checked for duplicate installs:

$ find / 2>/dev/null| grep bin/ruby
/usr/bin/ruby
/usr/bin/ruby2.0

$ find / 2>/dev/null| grep bin/rails
/usr/local/share/ruby/gems/2.0/gems/railties-4.1.0/bin/rails
/usr/local/share/ruby/gems/2.0/gems/railties-4.1.0/lib/rails/generators/rails/plugin/templates/bin/rails.tt
/usr/local/share/ruby/gems/2.0/gems/railties-4.1.0/lib/rails/generators/rails/app/templates/bin/rails
/usr/local/share/ruby/gems/2.0/gems/rails-4.1.0/guides/code/getting_started/bin/rails
/usr/local/bin/rails
/home/ec2-user/.gem/ruby/2.0/gems/rails-4.1.0/guides/code/getting_started/bin/rails

Answer 1

You would need to install io-console gem . Install it using following command:

gem install io-console

After this run rails -h

Also, run echo $PATH and make sure that you have /usr/local/bin in the path. If not, then you would need to add it.

Answer 2

So I had resolved this the same night, but somehow Stackoverflow didnt send me any notifications on the responses to the question, so I didnt know of these responses. This is what I ended up doing. It was essentially removing the ruby on rails installation and installing it from scratch. This was on a Amazon Web services server - linux flavor.

sudo yum update

$wget  https://raw.github.com/wayneeseguin/rvm/master/binscripts/rvm-installer

$ bash -s stable < rvm-installer

$ source /home/ec2-user/.rvm/scripts/rvm

$ rvm requirements

$ sudo yum erase ruby

$ rvm install ruby

$ rvm use ruby --default

$ rvm rubygems current

$ gem install rails   # this takes forever

After that it worked just fine.

Answer 3

I had exactly the same issue on AWS Elastic Beanstalk (Puma, Ruby 2, Rails 4.0):

> rails generate simple_form:install --bootstrap

/usr/local/share/ruby/gems/2.0/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require': cannot load such file -- io/console (LoadError)

I simply added:

gem 'io-console'

To the top of my Gemfile and ran bundle install again on the box for great success. Hopefully quicker than reinstalling rails for anyone else who runs in to this.

Answer 4

Thanks; you need io-console indeed. To make that work, install GCC. Rest is needed later on so:

yum -y install gcc mysql-devel ImageMagick-devel

Then,

gem install io-console

works and I could continue installing.