Rails server giving Readline support error

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!

score 17 · Answer 1 · answered Dec 06 '16 at 07:48

17

To fix this (for OSX, tested on Sierra), run following command in your shell -

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

answered Dec 06 '16 at 07:48

Abhinav Mehta

201
2
4

1

Thank you! I read about Zero's answer, but this one did the trick for me – Gambai Apr 02 '17 at 20:12
I changed libreadline.6.dylib with libreadline.7.dylib and it did the trick for me – Maruccio Feb 27 '19 at 19:40

score 8 · Answer 2 · answered Jul 03 '19 at 12:52

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

score 5 · Answer 3 · answered Oct 31 '16 at 10:33

5

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

answered Oct 31 '16 at 10:33

dom

509
1
7
13

score 3 · Answer 4 · answered Mar 05 '19 at 10:45

3

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.

answered Mar 05 '19 at 10:45

Faisal Raza

1,337
1
10
16

score 3 · Answer 5 · answered Mar 13 '19 at 09:19

3

Add this to the development group of gem.

gem 'rb-readline'

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

answered Mar 13 '19 at 09:19

Hidehiro NAGAOKA

417
3
12

score 2 · Accepted Answer · answered May 20 '15 at 15:46

2

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.

answered May 20 '15 at 15:46

Prakash Murthy

12,923
3
46
74

Great! My Rails server is up and running now... Your solution is working. Thanks! – Abraar Arique Diganto May 20 '15 at 16:04
Awesome. You can come back to `byebug` / other options for debugging in a rails app later on when you need it. – Prakash Murthy May 20 '15 at 16:06
Its working in my case as well. But I want to know why it is not working before as I have done what error says. I have installed the required package and then reinstalled ruby using 'rbenv' and by compiling from source as well but nothing works for me. – Neeraj Verma Sep 26 '15 at 19:38
11

this is not a solution to problem and why would beginner rails developer wouldn't need debugging, what if he comes from other language and is not a total newbie. – Przemek Mroczek Sep 30 '16 at 06:51
Agreed with prior comment. Not a solution. And, `byebug` is VERY useful, especially for beginners! – theUtherSide Oct 19 '16 at 01:56

score 2 · Answer 7 · answered Dec 16 '16 at 04:16

2

I resolved it by follwing way

brew unlink readline 
brew link readline --force

answered Dec 16 '16 at 04:16

Prakash

676
6
22

score 1 · Answer 8 · answered Oct 27 '16 at 04:54

1

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.

answered Oct 27 '16 at 04:54

Balaji Radhakrishnan

1,010
2
14
28

Rails server giving Readline support error

8 Answers8

July 2019 on Mac