I'm executing the file app.rb in my rails project and trying to step through it using the byebug gem, but I get an error saying 'byebug' is an undefined local variable. I'm running the code using the command 'ruby app.rb'. Is there a different way to step through a ruby file when executing it this way via the command line?
$ bundle install
Fetching gem metadata from https://rubygems.org/.....
Resolving dependencies...
Using byebug 6.0.2
Installing pg 0.18.3
Using bundler 1.6.2
Your bundle is complete!
Use `bundle show [gemname]` to see where a bundled gem is installed.
$ ruby app.rb
app.rb:17:in `block in <main>': undefined local variable or method `byebug' for main:Object (NameError)
from app.rb:15:in `glob'
from app.rb:15:in `<main>'
Looks like I just had to add require "byebug" at the top my app.rb file.
Another debugging option is the debugger gem:
require 'debugger'; debugger
https://github.com/cldwalker/debugger
Related
I'm trying to develop a ruby gem for practice and I'm wondering how do I require pry during development and test runs? Is there anyway to require the gem only during development? I'm on Ruby and not Rails and I don't think I have any environment variables setup to rely on. Is there a conventional way to do this?
and
Currently if I run code that hits the above line, I get this error:
NoMethodError: undefined method `pry' for #<Binding:0x007f8d3287c4d8>
from /Users/jwan/programming/interview_questions/gemini/jobcoin_client/lib/jobcoin_client/requests/connection.rb:18:in `post'
A few questions:
How do I properly require pry so this line doesn't throw an error when developing a gem?
I read Yahuda's post but I'm still unclear why adding dependencies in the gemspec vs adding dependencies in the Gemfile. What is the difference?
Currently, after I make changes to the ruby gem, I have to run these series of commands. Is there anything more efficient that I can do?
gem build jobcoin_client.gemspec
WARNING: no homepage specified
WARNING: open-ended dependency on pry (>= 0, development) is not recommended
if pry is semantically versioned, use:
add_development_dependency 'pry', '~> 0'
WARNING: See http://guides.rubygems.org/specification-reference/ for help
Successfully built RubyGem
Name: jobcoin_client
Version: 0.1.0
File: jobcoin_client-0.1.0.gem
$ gem install jobcoin_client
Successfully installed jobcoin_client-0.1.0
Parsing documentation for jobcoin_client-0.1.0
Done installing documentation for jobcoin_client after 0 seconds
1 gem installed
05:45 PM
$ irb
irb(main):001:0> require 'jobcoin_client'
=> true
irb(main):002:0> require 'pry'
=> false
You can install it to the system and use a boolean flag to conditionally require it and set breakpoints.
gem install pry
Then in code, something like this:
SET_BREAKPOINTS = ENV["SET_BREAKPOINTS"] == "true"
require 'pry' if SET_BREAKPOINTS
binding.pry if SET_BREAKPINTS
To turn breakpoints on, you can manipulate env through code:
ENV["SET_BREAKPOINTS"] = "true"
or when calling a script from bash:
env SET_BREAKPOINTS=true irb -r 'your_gem'
I'm trying to build my first gem. Using Ryan Biggs' tutorial as my guide, I did the following:
1) Created the gem scaffolding:
$ bundle gem hello_world
2) Edited the lib/hello_world.rb file:
require "hello_world/version"
module HelloWorld
def hi
"Hello world!"
end
end
3) Installed the gem via bundler:
$ cd hello_world
$ bundle install
At this point, if I run
$ bundle show hello_world
it shows
/Users/ykessler/gems/hello_world
so it looks like it installed.
But when I try to require the gem from irb:
require '/Users/ykessler/gems/hello_world'
it can't load it:
2.0.0-p195 :003 > require '/Users/ykessler/gems/hello_world'
LoadError: cannot load such file -- /Users/ykessler/gems/hello_world
from /Users/ykessler/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
from /Users/ykessler/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:45:in `require'
from (irb):3
from /Users/ykessler/.rvm/rubies/ruby-2.0.0-p195/bin/irb:16:in `<main>'
Where am I going wrong?
You need to run gem build hello_world.gemspec
Then to install it, you run gem install hello_world from the root of your gem project. That will install your local gem using the .gem file that we just created in your directory (not the gem from rubygems.org if it exists).
Now, if you run gem list, you should see it. You should now be able to require your gem and and access your library from other ruby code. All you have to write is require 'hello_world'. There is no need to type the full path. In fact, that's a bad idea.
This is all explained pretty clearly in the rubygems.org documentation (http://guides.rubygems.org/make-your-own-gem/). It's very clear, helpeful, and it's where I learned how to make my first gem.
I need to reference a local gem from a plain ruby script, without installing the gem. On the trail of How to refer a local gem in ruby?, i tried creating a Gemfile with the following setup:
%w(
custom_gem
another_custom_gem
).each do |dependency|
gem dependency, :path => File.expand_path("../../#{dependency}", __FILE__)
end
and the script looks like this:
require 'custom_gem'
CustomGem::Do.something
When I execute this with:
bundle exec ruby script.rb
I get:
script.rb:1:in `require': cannot load such file -- custom_gem (LoadError) from script.rb:1:in `<main>'
If I leave out the require 'custom_gem' , I get:
script.rb:3:in `<main>': uninitialized constant CustomGem (NameError)
I even tried without bundler, and just writing gem ... :path =>̣ ... in the script itself, but without results. Is there any other way of referencing custom gems from ruby scripts, without installing the gems locally?
Make sure that your gem name as same as in Gemfile (e.g. custom_gem)
# Gemfile
source "https://rubygems.org"
gem "custom_gem", path: "/home/username/path/to/custom_gem"
Don't forget to actually install this gem using bundler
bundle install
After that, the script should be ready to use by bundle exec ruby script.rb
# script.rb
require 'custom_gem'
CustomGem::Do.something
Without using a Gemfile, you can install a local version of a gem by running bundle exec rake install in the gem's root directory and then you can reference it just like any other installed gem.
I am currently running ruby-1.9.1 installed via RVM. I have been looking at using Merb, but when I try and run it I get this error:
sam#shiny-dev:~/Projects/mojo$ rake db:migrate
(in /home/sam/Projects/mojo)
Merb root at: /home/sam/Projects/mojo
/home/sam/.rvm/gems/ruby-1.9.1-p378#merb/gems/dm-validations-1.0.0/lib/dm-validations.rb:33: warning: already initialized constant OrderedHash
Loading init file from ./config/init.rb
Loading ./config/environments/development.rb
rake aborted!
no such file to load -- spec/rake/spectask
/home/sam/Projects/mojo/Rakefile:24:in `require'
(See full trace by running task with --trace)
I have installed rspec, but even in IRB I cannot require 'spec/rake/spectask' unless I also install rspec-rails (which I have now done).
Any ideas where I could even start?
Cheers,
Sam
I had the same problem with this on Rails 2.3.5. I ended up having to uninstall RSpec 2.0 and install RSpec 1.3.0 instead.
After 2 weeks I finally figured it out!
Edit your Gemfile and add the line:
gem "rspec", :require => "spec"
and you're away!
I am on Ubuntu10
sudo apt-get install ruby1.9.1-full
then download sources of rubygem 1.3.7 and install it
sudo ruby setup.rb
then, for example, install sinatra
sudo gem install sinatra
Finally open irb and type
require "rubygems"
require "sinatra"
and get error
LoadError: no such file to load -- sinatra
from (irb):2:in `require'
from (irb):2
from /usr/bin/irb:12:in `<main>'
I had exactly this problem. The problem is that gem and ruby disagree about where the gems live. Compare these:
ruby -e "puts Gem.path"
gem env
gem which sinatra
If you're like my setup, you'll notice that there's an entry in gem env's paths that isn't in Gem.path, and that's exactly where sinatra will claim to be. In my case, I had to add
export GEM_HOME=/usr/lib/ruby/gems/1.9.1
to my .profile. Then everyone was happy.
Execute
sudo gem install sinatra --verbose
and note the path where the gem is getting installed.
Then try this in irb
puts $LOAD_PATH
and make sure that gem is installed in one of the directories in $LOAD_PATH
And ideally just start using http://rvm.beginrescueend.com/
I usually hit this error when I forget:
require 'rubygems'
It'd be helpful if you provided the actual code sample, though, what gem you want to require, and what Ruby version you're using if this doesn't solve the problem.
This was before here on SO quite a few times. Problem is that you probably have two versions of ruby. The one is installing the gem and the other one is trying to use it. Do this in terminal:
$ which -a ruby
Or this:
$ which -a gem
to see if you have more than one version of ruby/gem installed. If so - remove one version (via $ rm or package manager of your system).
I use ruby gems 1.8.7 for a project. I was getting the same error. Use the line require 'rubygems'. It must always be the first require statement, otherwise you can get an error. In my code, I had
require 'watir'
require 'rubygems'
# more code
I got the error - in `require': no such file to load -- watir (LoadError).
When I put rubygems first, the error went away and everything worked. I don't know
why this happens.
Btw, I tried user24359 answer and it did not help me.
C:\code>ruby -e "puts Gem.path"
-e:1: uninitialized constant Gem (NameError)