I have developed a simple ruby application without any MVC, and runs on command prompt using ruby 1.9.2 . It also has a Gemfile. I want this application to run on machines running ruby 1.8.7 and 1.9.3 as well. So how can I set it right for multiple environments.
Please Guide.
Thanks
At first you have to make sure that your code is compatible with the syntax of ruby 1.8 and 1.9 https://stackoverflow.com/a/21621/335523
Then make sure that the gems you used support both versions of ruby. (Read through their github page or documentation)
If you are using gems that do not suport both versions of ruby you have to find alternative gems that provide the same functionality in each environment and specify them in your gem file like this:
gem 'rcov', :platforms => :ruby_18
gem 'simplecov', :platforms => :ruby_19
Related
In ~/src/project/ containing all the files, I'm attempting to run bundle and bundle install, but it tells me I need a gem called "buff-extensions" and that gem installer requires Ruby version >= 2.2.0 to work properly.
When I ran ruby --version, it said Ruby 2.2.4p230 is being used when run from that directory.
I know there are several versions of Ruby on the machine in several places, and I'm struggling to follow the paths and figure out which technology is using which piece.
The Bundler docs spell this out:
You can specify the required version of Ruby in the Gemfile with ruby. If the Gemfile is loaded on a different Ruby version, Bundler will raise an exception with an explanation.
ruby '1.9.3'
What this means is that this app has a dependency to a Ruby VM that is ABI compatible with 1.9.3. If the version check does not match, Bundler will raise an exception. This will ensure the running code matches. You can be more specific with the :engine and :engine_version options.
ruby '1.9.3', :engine => 'jruby', :engine_version => '1.6.7'
I finally figured out the exact incantation in order to get the intended result, and I now realize the situation is unreasonable to expect any stranger to attempt to answer.
It involved chef, and I was supposed to run chef exec bundle.
So I am developing a Sinatra for both windows and linux. The problem is I'm using Thin instead of Webrick and eventmachine for windows only works with a pre-release version while linux uses the latest stable. in the gemfile you of course cannot include the same gem with different versions like so:
gem "eventmachine", "~> 1.0.0.beta.4.1", :group => :development_win
gem "eventmachine", group => :development_linux
gem "thin
I was wondering if there was a way to work around this, maybe using one gemfile for windows and one gemfile for linux, what would the command be to load one or the other.
Alternatively is there a way to perhaps in git manage just the gemfile for two different platforms, perhaps through a branch for just the file (don't know if that's possible from what I've read of git branches).
You can do it like that:
# Windows
gem "eventmachine", "~> 1.0.0.beta.4.1", :platform => [:mswin, :mingw]
# C Ruby (MRI) or Rubinius, but NOT Windows
gem "eventmachine", :platform => :ruby
Full list of available platforms:
ruby C Ruby (MRI) or Rubinius, but NOT Windows
ruby_18 ruby AND version 1.8
ruby_19 ruby AND version 1.9
ruby_20 ruby AND version 2.0
mri Same as ruby, but not Rubinius
mri_18 mri AND version 1.8
mri_19 mri AND version 1.9
mri_20 mri AND version 2.0
rbx Same as ruby, but only Rubinius (not MRI)
jruby JRuby
mswin Windows
mingw Windows 'mingw32' platform (aka RubyInstaller)
mingw_18 mingw AND version 1.8
mingw_19 mingw AND version 1.9
mingw_20 mingw AND version 2.0
You can find more information in Gemfile(5) man page here (see 'Platforms' section).
Another approach is to use RUBY_PLATFORM constant:
if RUBY_PLATFORM =~ /win32/
gem "eventmachine", "~> 1.0.0.beta.4.1"
else
gem "eventmachine"
end
I haven't seen full list of available values for RUBY_PLATFORM but you can run
ruby -e 'puts RUBY_PLATFORM'
on both your platforms and see the difference.
You can use the --gemfile option to use different gemfiles for different platforms. See the documentation here
http://gembundler.com/man/bundle-config.1.html
You need multiple versions (all with the same name) of a gem. Therefore, currently with Bundler, you need multiple, simultaneous Bundler dependency snapshot 'lock' files. This is possible, if your developers make use of Bundler's gemfile configuration setting. They might do this either:
By making use of environment variable BUNDLE_GEMFILE (on the command line or in .bash_profile); or
(Probably less desirably) in .bundle/config (globally, in their home directories).
Thus, safely, Bundler can create (and presumably automatically later use, given the same configuration settings) e.g. Gemfile-linux.lock and Gemfile-windows.lock.
Although this basic approach seems workable, it's not very DRY. However, this improves if, e.g., both Gemfile-linux and Gemfile-windows automatically incorporate whatever Gemfile statements they share in common: i.e., if they include the statement:
::Kernel.eval(File.open('Gemfile-common','r'){|f| f.read},::Kernel.binding)
I am currently reading through this guide: http://guides.rubygems.org/what-is-a-gem/
Under the third section ("Requiring code"), it says that if I run require 'rake', it should fail, because "because RubyGems isn’t loaded yet.". However, when I run require 'rake', (without running require 'rubygems', it works! Is the guide incorrect or am I using a wrong version of Ruby or has something changed?
You are probably running Ruby 1.9.
Per The RubyGems User Guide:
The default Ruby 1.9 package now
includes RubyGems by default on most
platforms (presently Debian based
systems split this out into a separate
package). This means that on Ruby 1.9
and above, you will not need to
require 'rubygems' in order to load
gem libraries.
If you have RUBYOPT=rubygems set in your environment when you launch Ruby, then Ruby Gems will automatically be required. Or if you launch ruby with the argument -rubygems, which is equivalent. Or if you're using Ruby 1.9 or later, Rubygems should automatically be required.
One (or more) of these things is probably true on your system.
I'm using Ruby 1.9.2 (Yarv).
When I install gems I just use "gem install ".
How can I know which Ruby version they are written in: 1.8.7, 1.9.1 or 1.9.2?
If I'm using the latest version and I install a gem that is written in 1.8.7, then that gem doesn't work?
Eg. Yardstick gem seems to not work with 1.9.2 but perfectly with 1.8.7.
How do you check what version each gem is using?
Could someone enlighten this topic for me.
Unfortunatelly there is no definitive way to check that as there are so many versions and variants or Ruby interpreters (Ruby, JRuby, Iron Ruby) and system platforms. Also one gem which is pure Ruby may not work on all platforms with same interpereter verson, because some OS specific properties could be used.
So you must trust the autor or docs he/she provided. Another way to make sure that your platform is right for gem just run tests enclosed to gem - every well written gem should have such.
There is also small tip: if file contains
# -*- encoding: utf-8 -*-
then autor probably developed the gem with 1.9.x in mind.
There's a website for answering the question: "Is it Ruby 1.9?"
http://isitruby19.com/
It doesn't look like anyone has reported on Yardstick yet:
http://isitruby19.com/yardstick
You could be the first, and report that it's broken in 1.9.
Is it possible to add a gem dependency only if the person is using a certain version of ruby?
Background: I'm working on a fork of a project that uses Test::Unit::Autorunner and the like. They are part of the standard library in ruby 1.8, but aren't part of the standard library in 1.9.1, and is instead in the "test-unit" gem. I want to add a dependency that says that if someone's using ruby 1.9.1 or later, install the "test-unit" gem, but if they're using 1.8 or earlier, they don't need to install anything.
If you look at the gemspec documentation for add_dependency, there isn't an option for a ruby version. Perhaps you could use the post_install_message attribute to tell the user to install the gem if they're using ruby 1.9.
I did this exact thing for a project. The trick is to add the script as an extension, which will then get executed at install time on the user's machine.
Here are code snippets and links to our github:
First, when in the gemspec (we're actually using a Rakefile to generate it, but the result ends up the same) source
# This file *needs* to be named this, there are other files
# for other extension processors
s.extensions << 'ext/mkrf_conf.rb'
And then the relevant lines in that mkrf_conf.rb source
require 'rubygems/dependency_installer.rb'
inst = Gem::DependencyInstaller.new
inst.install "test-unit" if RUBY_VERSION > "1.9"
Gem doesn't support conditional dependencies (except on gem builder's environment -as noted above), and bundler is not a viable option to solve this either - see https://github.com/carlhuda/bundler/issues/1281
hay ... i'm kind of a ruby newbie ... if this is the best way to do it.
any way ... i wish i can do that using only Ruby .... though u can use your operating system shell to do that, by using this in your program installer, just execute (works for Linux based operating systems):
$ruby --version
(u can execute that from a ruby installer file, just like: ruby --version)
and put a possibility according to output, if it's 1.9.1 add an extra line to execute:
$ sudo gem install gem_name
else, just leave it be.
Checkout this tutorial in the Ruby Programming wikibook.
Tt shows how to install different versions of dependencies depending on what version of ruby the installee is using.
(short answer--it ain't as easy as it should be)
You can't. You need to build two gems, one with
spec.required_ruby_version = '~> 1.8.6'
and one with
spec.required_ruby_version = '~> 1.9.1'
spec.add_dependency 'test-unit', '~> 2.0.5'
Gemspecs are just ruby files anyway, so you can execute any ruby code inside them, so:
spec.add_dependency = 'test-unit', '>= 2.0' if RUBY_VERSION =~ '1.9'
EDIT: Specs run only on the builders machine.