I am in the early stages of learning Ruby and want to learn how to debug a gem, but am having trouble finding learning resources around this. A simple example would go a long way for me.
Is debugger the preferred debugger? Where do I require it? How do I set breakpoints with it?
Note: I am making an educated guess that the debugging process may be different depending on the gem that needs debugging, so for reference I am particularly interested in debugging certain issues with Compass.
OK, figured this out on my own. Here were the steps I took..
I am running Ruby 1.9.3 (determined by running ruby -v), so after testing ruby-debug and ruby-debug19, I determined these debuggers were no longer maintained, or at least didn't work properly with my install of ruby1.9.3-p125. This lead me to debugger.
The install instructions that worked were:
$ gem install debugger -- --with-ruby-include=PATH_TO_HEADERS
The PATH_TO_HEADERS on my machine, was simply the source location of ruby:
/Users/myusername/.rvm/src/ruby-1.9.3-p125/
Since I was particularly determined to debug the Compass compiler, I did the following:
Cloned the source: $ git clone git://github.com/chriseppstein/compass.git
Checked existing compass version first $ compass -v which was 13.0
Edited VERSION.yml and increased the patch number (to 13.1) so it didn't conflict with my existing install.
Edited the .rb of the file I wanted to debug, which was lib/compass/compiler.rb and added this line at the top: require 'debugger'; debugger
Built the gem: gem build compass.gemspec
Installed the newly compiled gem: sudo gem install compass-0.13.2.058ead2.gem
Compiled an existing compass based project that I was experiencing problems with, and started debugging.
When I was done debugging, I uninstalled the debugging version with sudo gem uninstall compass and chose the number corresponding to Compass 13.2.
Note about step 7: Since debugger has the same debugging commands as ruby-debug/ruby-debug19, I was able to follow existing tutorials around debugging steps..
Such as this RailsCast:
http://railscasts.com/episodes/54-debugging-with-ruby-debug
And this blog (and linked cheat sheet):
http://pivotallabs.com/users/chad/blog/articles/366-ruby-debug-in-30-seconds-we-don-t-need-no-stinkin-gui-
If you have other debugger tutorials, pointers, tips, etc, please post them.
Related
In our Rails application we do require 'RRD' at some point, but that results in a cannot load such file -- RRD. So obviously I used homebrew to install rrdtool, but the error remains.
The docs at https://oss.oetiker.ch/rrdtool/prog/rrdruby.en.html provide two options:
Either:
$: << '/path/to/rrdtool/lib/ruby/1.8/i386-linux'
require "RRD"
In my /opt/homebrew/Cellar/rrdtool/1.8.0/lib directory there's no mention of ruby, which is because of the --disable-ruby-site-install flag in the formula, because when I skip that flag I do actually get something: /opt/homebrew/Cellar/rrdtool/1.8.0/lib/ruby/2.6.0/universal-darwin21. However replacing the path/to string with this path still gives the error.
Or:
If you use the --ruby-site-install configure option you can drop the $: line since the RRDtool module will be found automatically.
Which is a little confusing (and probably outdated) because here it seems that ruby site install is disabled by default and you have to enable it proactively, whereas in the formula it's actually actively disabled.
Either way: both options didn't do the trick for me and if there's a solution without homebrew that's also fine.
For good measure: I'm on macOS Monterey
TL;DR
For the most part, I'd say that using a non-standard gem without a Ruby version manager is your main issue. There are instructions on the rrdruby site for installing it, but they don't follow typical conventions, so your mileage will vary.
Some Practical Suggestions
The require keyword is for gems, not binaries. You need to have an rrdtool-related gem installed, available to your Ruby instance (usually through a Bundler Gemfile or gemspec, or via the RUBYOPTS environment variable or your in-process Ruby $LOAD_PATH), and then require the correct name of the gem in your code. For example, using the older rrd-ffi gem:
# use sudo if you're installing it to the system,
# but I would strongly recommend a ruby version
# manager instead
gem install rrd-ffi
# in your Ruby class/module file
require "rrd"
For the gem you seem to be using, you have to compile the gem first to make it usable, and then ensure it's available in your Ruby $LOAD_PATH (or other gem lookup mechanism) before trying to require it. The error message you're seeing is basically telling you that a gem with that name is not available as called within any of the standard lookup locations.
Again, I'd suggest reading the build documentation for your gem, and then seeing if you can install it as part of a Bundler bundle, RVM gemset, or other non-system approach if you can. Otherwise, follow the directions for the rrdruby tool, which is not available as a standard Rubygems.org gem, in order to make it available before trying to require it.
Beware of Outdated or Non-Standard Gems
Most of the RRD gems I found were quite old; most were 7-8 years old or older, so their compatibility with current Rubies is potentially suspect. The gem-builder you're using is newer, but doesn't seem to be designed as a standard gem, so you need to build it and install it in a suitable lookup path before it can be required. Installing gems as system gems is almost always a bad idea, so I'd strongly recommend building it from source and using a ruby version manager rather than following the rrdtool author's atypical suggestions. YMMV.
I'm opening ruby file via RubyMine. IDE suggests installing RuboCop. I accept it, but after a few seconds it shows:
Following gems were not installed: rubocop (1.0.0): Cancelled
Documentation says its problem with interpreter path. Problem is its already set. Even when i try to add it like documentation says, it won't let me, because its already set.
Any ideas what i can do? I have been using VisualStudio Code without issues before it, but Ruby support is pretty poor, i had to use terminal, while for example python has full support and you can just run program with one button.
Ruby 2.2.2 on Ubuntu
I have been following the saasbook tutorial on Rails and am getting to grips with the workflow.
I am confused about debugger which some sources says us now 'included' post Ruby version 2. It fails to compile on the example projects and many people have the same issue.
I have found that any bundle install that I try to do with the examples. (see here) (possibly after a bundle update) will fail on trying to 'gem install debugger -v '1.6.x''.
I have found that by commenting out the debugger line in the Gemfile will get me around this hurdle and upon firing up the Rails server, everything seems to work. I also have to change the Ruby version to my current one (2.2.2).
I am assuming that I am working with pre version 2 Ruby examples and this is good to do post version 2.
Am I correct? What has happened to the debugger post version 2?
The debugger gem is not supported on Ruby 1.9. See the debugger readme on GitHub here. If you need a command line debugger for newer versions of Ruby you can use byebug.
You can use the basic built in debugger if you prefer. Simply put require 'debug' anywhere in your source code and the Ruby interpretor will stop at that point and allow you to inspect variables etc. You do not need to install or add any additional gems to your Gemfile to use this as it is built in. See the built in debugger documentation here
I'm building a simple web app on Sinatra that I can deploy like a gem to artifactory; to start with I'm getting everything setup.
Here's what I've done:
I've got the the gemspec done so I can deploy like a gem
I've got sinatra modular set up with a basic 'hello world' page
I've got Rspec setup for testing (hello world test passes)
I've got rake tasks to make things easier (booting up sinatra, building the gem, running tests, etc)
Now I need to move Sinatra from Webrick to somthing a bit more robust and that's this is where I'm hitting a wall.
I've tried Unicorn,thin and Puma but they all won't install and I don't know what to do.
They all fail at Building Native extensions, I don't know what to do.
I'm using windows 8.1 (i'd rather be doing this on ubuntu but the company uses windows and to be honest I like a challenge) ruby 2.1 and I have devkit installed (and it's working now, wouldn't last night).
From what I've read Unicorn won't work on windows so the best bet is to go with thin but that fails with: extconf.rb
checking for main() in -lc... *** extconf.rb failed ***
It mentions that I need the devkit installed (it is the first line is Temporarily enhancing PATH to include DevKit...)
Despite this it fails, I tried doing what I found in this but that didn't help ( Installing event machine didn't do anything).
I'm at a loss of what to do next.
EDIT:
Whilst I've solved the problem of getting Thin to install it now has a differant error
IT can't load eventmachine.
EDIT:
It all comes down to the fact that the Devkit wasn't being recognised or it didn't install properly or something. I wonder why.
I've tried Unicorn,thin and Puma but they all won't install and I don't know what to do. They all fail at Building Native extensions, I don't know what to do.
The reason these are failing is that many ruby gems use native C extensions which expect to be compiled and installed on a linux or unix environment.
Doing any sort of Ruby development work on a Windows machine is an exercise in sadomasochism.
I strongly recommend you install VirtualBox, download an Ubuntu or similar linux virtual machine image, boot it, configure it, and use it as your development webserver. You can continue to edit your code in windows, but you will be running it in a sane environment.
Ultimately, you may have to learn some new skills, but you will save yourself an enormous amount of frustration by moving off windows as your development platform.
I managed to get thin installed but it wasn't easy
I wiped every bit of ruby from my machine, including all references in the registry, got rid of pik as well.
I then followed these steps (that I worked out along with an answer from another question) and it now works
install rubyinstaller 2.1.3
install devkit
gem install thin --platform=[win64]
notepad C:\Ruby21-x64\lib\ruby\gems\2.1.0\gems\eventmachine-1.0.3\ext\project.h #append line 97 with //
cd C:\Ruby21-x64\lib\ruby\gems\2.1.0\gems\eventmachine-1.0.3
gem build eventmachine.gemspec
move eventmachine-1.0.3.gem up one directory
cd ..
gem install eventmachine-1.0.3.gem
del the gemfile
cd
gem install thin --platform=[win64]
A bit of a job BUT it worked,
The answer in question isthis one.
specifically
2) edited the file:
c:\Ruby21-x64\lib\ruby\gems\2.0.0\gems\eventmachine-1.0.3\ext\project.h
and commented the line 97
//typedef int pid_t; for a more robust correction, checkout the
solution here
https://github.com/eventmachine/eventmachine/pull/450/files
3) then, i've opened command prompt, and went to the gem folder
c:\Ruby21-x64\lib\ruby\gems\2.0.0\gems\eventmachine-1.0.3 and run:
gem build eventmachine.gemspec
In the end, after hammering my head against a wall, on a suggestion I installed chef-client and using the embedded ruby allowed it to work, that said it only uses ruby 1.9.3 but it works so for now it will have to do.
I'm setting up a project that uses SASS, which uses FSEvents to keep from polling the disk. It seems that this doesn't play nice with RVM, however. That means that when I run sass --watch I get this warning:
Warning: Unable to load CarbonCore. FSEvents will be unavailable.
I realize that it will still work, but I don't want to be polling my disk constantly. I want to get it working with FSEvents. The best information I could find about this was this thread:
http://groups.google.com/group/compass-users/browse_thread/thread/df7d9d0da9ec1eb1
I reinstalled my RVM Ruby (using 1.9.2) as described by Brandon Mathis and downloaded the linked RubyCocoa. However, I get an error on the first step of installing RubyCocoa:
[rvm 1.9.2] ~/Downloads/RubyCocoa-1.0.0 $ ruby install.rb config --build-universal=yes
install.rb: entering config phase...
create ext/rubycocoa/extconf.rb
create framework/GeneratedConfig.xcconfig
create framework/src/objc/Version.h
create tests/Makefile
---> framework
create /Users/xxx/Downloads/RubyCocoa-1.0.0/framework/src/objc/osx_ruby.h ...
config failed
hook /Users/xxx/Downloads/RubyCocoa-1.0.0/framework/post-config.rb failed:
No such file or directory - /Users/xxx/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/x86_64-darwin10.6.0/ruby.h
try 'ruby install.rb --help' for usage
It looks like the problem stems from this being an older version of RubyCocoa (I notice the missing file has 1.9.1 in the path), but in the Google Groups post, Brandon Mathis says specifically to use the version he links and not the newest one.
Does anyone know how to get this configured, or have a link to a recent, hopefully simpler and clearer guide to getting FSEvents working with RVM?
Versions in question:
RVM 1.2.0
Ruby 1.9.2 patch level 136 (installed via RVM)
Mac OS X 10.6.6
HAML gem 3.0.25 (SASS is part of HAML)
Thanks!
I wrote FSSM, which is what HAML/SASS/Compass use for their filesystem watching backend. While rubycocoa isn't supported in 1.9.x, the latest git version of FSSM has pretty solid support for rb-fsevent. This library currently has other limitations, like only being able to monitor one path (parent directory is a must here), but I'm working on it. ;)
I'd highly suggest installing rb-fsevent, and then FSSM from github: https://github.com/ttilley/fssm
If you have any problems, please don't hesitate to file an issue in the tracker. FSSM is a currently maintained project, and it was originally written to help Chris Eppstein out with providing watch functionality in compass (which was later adopted in sass itself). Ease of use via these libraries is my absolute top priority.
This is kind of a lost battle. You can copy the contents of the include/ruby folder from the Ruby source code to that location /Users/xxx/.rvm/rubies/ruby-1.9.2-p136/lib/ruby/1.9.1/x86_64-darwin10.6.0/ which will let you run the config command, but after that you will get a lot of errors on the setup command and you won't be able to install it all. People say RubyCocoa doesn't work with 1.9.2 and I don't know if anyone managed to make it work.
I tried the FSSM method above, to no avail...
Gemfile now has:
group :development do
gem 'rb-fsevent'
gem 'fssm', :git => 'https://github.com/ttilley/fssm.git'
end
which installs:
fssm (0.2.6.1)
rb-fsevent (0.4.0)
Still getting this tho:
Warning: Unable to load CarbonCore. FSEvents will be unavailable.
Anyone have install steps to make FSSM work nicely?