Ruby publishes security issues and MRI updates on ruby-lang.org. Unfortunately there is no straight-forward way to subscribe to these updates via e-mail.

I fixed this for me by taking their RSS feed and submitting it to Blogtrottr. Blogtrottr is an RSS-to-email service that sends you an e-mail whenever the feed updates.

Ubuntu 12.04 LTS x64, Ruby 1.8.7, Rails 2.13, PDFKit 0.5.4, Phusion Passenger Apache 2

I ran into this, when I started using passenger to deal with the Single Thread Issue which caused my webrick to deadlock when an ActionController::RoutingError (No route matches "...") occurred.

These steps brought me a little further

(1) assert dependencies are installed

 sudo aptitude install openssl build-essential xorg libssl-dev

(2) only for 64bits OS Run one by one the follo...

After reading, you will know why and how runners.each(&:run) works. Here some tidbits:

& can be quite confusing because it has a different meaning depending on the context in which it's used.

&object is evaluated in the following way:

• if object is a block, it converts the block into a simple proc.
• if object is a Proc, it converts the object into a block while preserving the lambda? status of the object.
• if object is not a Proc, it first calls #to_proc on the object and then converts it into a block.

Today I ran into trouble installing therubyracer on Ruby 1.8. The installation failed with

*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
   ...

You're better off using debugger-ruby_core_source:

gem install debugger-ruby_core_source

If you can't do this, try the following.

Here is how to fix the following error when installing the debugger gem fails:

Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension

Note: The following example is for a project using Ruby 1.9.3-p448 -- adjust accordingly for your project.

1. Fetch the source for your Ruby version, if you do not yet have it:

   rvm fetch ruby-1.9.3-p448
   

2. Install t...

It is good programming practice to Don't Repeat Yourself (or DRY). In Ruby on Rails we keep our code DRY by sharing behavior by using inheritance, modules, traits or partials.

When you reuse behavior you want to reuse tests as well. You are probably already reusing examples in unit tests. Unfortunately it is much harder to reuse code when writing integration tests with Cucumber, where you need to...

Geordi 0.16+ supports running selenium tests with project-specific firefox versions.

Just update the gem. It will still default to using the old 5.0.1 firefox. If you want another one, add a file .firefox-version to your project, containing your preferred version.

geordi cucumber will prompt (and guide) you to install the given version. You can delete any old installation sitting in /opt/firefox-for-selenium if you have one.

If you need to test interaction with a remote API, check out the VCR gem as an alternative to Webmock or stubbing hell.

The idea behind VCR is that is performs real HTTP requests and logs the interaction in a .yml file. When you run the test again, requests and responses are stubbed from the log and the test can run offline.

It's a great way to mock network requests to an external service without going through the pain of log...

So you're switching to PostgreSQL from MySQL? Here is some help...

General hints on PostgreSQL

• \? opens the command overview
• \d lists things: \du lists users, \dt lists tables etc

Command comparison

The mysql2 gem in version 0.3.13 might break while compiling on older patch releases of Ruby 1.9.3 within rvm:

*** [err :: server] ruby: symbol lookup error: /path/to/deployment/shared/bundle/ruby/1.9.1/gems/mysql2-0.3.13/lib/mysql2/mysql2.so: undefined symbol: rb_wait_for_single_fd
*** [err :: server] ruby: symbol lookup error: /path/to/deployment/shared/bundle/ruby/1.9.1/gems/mysql2-0.3.13/lib/mysql2/mysql2.so: undefined symbol: rb_wait_for_single_fd

Fixating mysql2 to version 0.3.11 helped.

dusen 0.4.8 and edge_rider 0.2.3 no longer depend on Rails (they still depend on ActiveRecord). That means you can use them e.g. with Sinatra.

Do not use .rvmrc files to specify Ruby version and gemset configuration any longer, it's deprecated and not considered by other Ruby version managers such as rbenv.

If you want to migrate an existing .rvmrc you can use rvm rvmrc to .ruby-version.
Put gemset specification into .ruby-gemset.

Creating the .ruby-version file on your own, just make a file containing e.g.

1.8.7

Attention: Don't clutter other developers rvms with several unecessary ruby patch levels

When you use the rvm command

rvm --ruby-version use 1....

After running bundler / gem install I could not load nokogiri lately. It died with cannot load such file -- nokogiri/nokogiri.
This is not a problem of the gem but is due to a broken native extensions installation routine.

When installing nokogiri manually and with verbose output by using gem install -V nokogiri -v 1.5.6, you can see the problem scrolling by when the native extension is built:

/usr/bin//install -c -m 0755 nokogiri.so /home/thomas/.rvm/gems/ruby-2.0.0-p247/gems/nokogiri-1.5.6/lib/home/thomas/.rvm/rubies/ruby-2.0.0-p...

bundle open BUNDLED_GEM will open the BUNDLED_GEM's source code in your default editor.

Bundler 1.4.0 (still beta) can install gems in parallel, making a run of bundle install much faster.

Ruby's private keyword might do a lot less than you think.

"private" does not apply to class methods defined on self

This does not make anything private:

class Foo

  private

  def self.foo
    'foo'
  end
  
end

You need to use private_class_method instead:

class Foo

  def self.foo
    'foo'
  end
  
  private_class_method :foo
  
end

"private" does not apply to define_method

This does not make anythin...

RubyLTS is a long term supported fork of Ruby 1.8 that will continue to receive security updates for the forseeable future.

The new exception_notification has awesome options like :ignore_crawlers => true and :ignore_if => lambda { ... }. These options should be helpful in ensuring every notifications means something actionable (instead of a long log of failures that just scrolls by).

Note that you should not ignore crawlers by default. Ideally, cool URLs never change and always respond with a helpful redirect or similar.

Ignore Errors like this:

# config/initializers/exception_notification.rb

Ex...

Consul 0.9 comes with many new features to optimize powers that only check access to a given record. e.g. Power.current.post?(Post.last). See below for details.

Powers that only check a given object

Sometimes it is not convenient to define powers as a collection. Sometimes you only want to store a method that
checks whether a given object is accessible.

To do so, simply define a power that ends in a question mark:

class Power
  ...

  power :upd...

The linked page lists and explains global Ruby "dollar" variables, such as:

• $: (load path)
• $* (ARGV)
• $? (Last exit status)
• $$ (PID)
• $~ (MatchData from last successful match)
• ...and many more you'll need when reading weird code.

Regex

• $~ (last MatchData)
• $1 $2 $3 $4 (match groups from the last pattern match)
• $& (last matched string)
• $+ (last match group)
• `$`` (the string before the last match)
• $' (the string after the last match

See [this extensive list of variables](http://www.tu...

Ruby 1.9 brings a shorter way to define lambdas using the -> operator:

twice = -> (x) { 2 * x }
twice.call(5) # => 10

This is equivalent to:

twice = lambda {|x| 2 * x }
twice.call(5) # => 10

Note that the syntax is subtly different from Coffeescript where you define function parameters before the arrow: (x) -> { 2 * x }.

Using CSS sprites for background images is a technique for optimizing page load time by combining smaller images into a larger image sprite.

There are ongoing arguments on how useful this still is, as modern browsers become more comfortable to load images in parallel. However, many major websites still use them, for example amazon, [facebook](...

Did you know you can do in-place batch processing with plain ruby?

The following script will in-place replace "foo" with "bar" in all files you feed it. Call it with ./my_script path/to/my/files/*

#!ruby -i -p
$_.gsub!(/foo/, "bar")

"'-i -p" means:

Ruby will run your script once for each line in each file. The line will be placed in $_. The value of $_ at the end of your script will be written back to the file.

Shorter

Using the Kernel#gsub shorthand for $_.gsub!:

#!ruby -i -p
gsub(/foo/, "bar")

S...