Rails服务器给出Readline支持错误

Question

I'm new to Ruby on Rails and I'm trying to start the RoR server. But when I run the command rails server it gives me the following error:

Sorry, you can't use byebug without Readline. To solve this, you need to
    rebuild Ruby with Readline support. If using Ubuntu, try `sudo apt-get
    install libreadline-dev` and then reinstall your Ruby.
bin/rails:6: warning: already initialized constant APP_PATH
/home/abraar/ror/bin/rails:6: warning: previous definition of     APP_PATH     was here
Usage: rails COMMAND [ARGS]

I'm using rbenv with Ruby 2.2.2 and Rails 4.2.1 I tried following the instructions on this blog post http://vvv.tobiassjosten.net/ruby/readline-in-ruby-with-rbenv/ but it's not working.

Any solutions?

Thanks!

Answer 1

要修复此问题（对于OSX，在Sierra上测试），请在shell中运行以下命令 -

ln -s /usr/local/opt/readline/lib/libreadline.dylib /usr/local/opt/readline/lib/libreadline.6.dylib

Answer 2

I solved the issue by (commands for mac with homebrew and rbenv):

• installing readline brew install readline
• reinstalling / recompiling ruby rbenv install 2.3.1

Answer 3

July 2019 on Mac

I faced this same issue on my machine & running the following command solved it, note that even if you have version 8 of readline you still need to link to version 7 as shown:

ln -s /usr/local/opt/readline/lib/libreadline.dylib /usr/local/opt/readline/lib/libreadline.7.dylib

Answer 4

Add this to the development group of gem.

gem 'rb-readline'

https://github.com/deivid-rodriguez/byebug/issues/289#issuecomment-251383465

Answer 5

byebug is a gem used for debugging.

The new app generator for rails includes it by default in the development & test environments with the following lines :

group :development, :test do
<% if RUBY_ENGINE == 'ruby' -%>
  # Call 'byebug' anywhere in the code to stop execution and get a debugger console
  gem 'byebug'

I don't think it is important for a newcomer to be able to use it. I would recommend commenting out that line in the Gemfile, run bundle install and continue with your rails learning adventure.

Answer 6

I resolved it by follwing way

brew unlink readline 
brew link readline --force

Answer 7

I was facing the following error:

Sorry, you can't use byebug without Readline

Reinstalling ruby resolved this for me (using rvm):

rvm reinstall 2.1.5

You can replace ruby version ie, 2.1.5 with the one you want to reinstall.

Answer 8

If you are in a hurry,

Open your byebug's history.rb

/Users/user/.rvm/gems/ruby-2.1.5@rails/gems/byebug-9.0.5/lib/byebug/history.rb

and comment out the following line,

require 'readline'

But, It is recommended to use byebug to debug.