How can I manage rubygems version with bundler? - ruby

I just started learning Ruby, and for my sandbox I use latest Rubygems version, according to examples and tutorials.
At the same time I have Redmine, which requires Rubygems 1.6.2.
To manage gem versions I use bundler, but can I use it to manage Rubygems version too?

I dont think so - I believe it uses your current rubygem from the environment.
However you can use rvm to manage the rubygems version, so if you install it and have a project specific gemset in your .rvmrc file.
I think rvm is OSX/unix only - there is an alternative for Windows I believe.

Related

Bundler version for Ruby 2.3.8?

I currently have 2 ruby versions, 2.5.5 and 2.3.8, I am managing them with rbenv, and for gems, I use bundler to manage my specific gem versions. I have an issue when I want to switch to a project that uses 2.3.8 or a version that has to do with Ruby version 2.3.
My question is how do I get bundler to run the command to bundle install interact with my 2.3 projects.
My current version of bundler is 2.0.2.
I have already tried installing a lower version of bundler of which the bundler website claims to interact with ruby version 2.3.
I thought that if I specified the command to run bundle _version_ install it would work, but it still gave me the response that it needed ruby version 2.5 for bundler to work.
Lots of help appreciated.
In some situations, isolation can help. I would like to recommend rvm (https://github.com/rvm/rvm) for managing ruby versions. This tool is very similar to rbenv but in comparison, it allows you to create gemsets which are kind of containers of gems for special purposes. For instance:
rvm install 2.5.5 --disable-binary
rvm use 2.5.5#name-of-gemset --create
gem install bundler
bundle install # inside your project folder with Gemfile
I think that you will not have problems with versions again.

How to upgrade from ruby 2.2.3 to ruby 2.3.0

My current Ruby version is 2.2.3 and I want to upgrade it to 2.3.0.
I use rbenv using this guide: gorails.com/setup/ubuntu/16.04
How do I upgrade my Ruby version? And when I upgrade, does it affect anything that I need to be aware of?
This answer had been written to address the original question, which did not specify rbenv as a preferred approach. Although the question changed after this answer was written, the answer has been retained to help users that may be using RVM to upgrade/manage their Ruby installations.
See the rbenv answer for details on using rbenv for the same purpose.
Use RVM or another Ruby version manager. This is far superior to installing a new system Ruby in most cases.
If you're upgrading your system Ruby, you have a number of things to keep in mind:
what other dependencies are there on that Ruby version?
are all of the gems going to be available after upgrade?
which applications are using the existing Ruby version and what can/will break after upgrade?
are there any other users using the existing Ruby that need to be aware of (and prepare for) the change?
With a Ruby version manager, you eliminate most of these concerns. You can run multiple Ruby versions on the same machine, which gives you the ability to test backward and forward compatibility. It also lets you experiment with the newer Ruby versions to make sure that they're fully stable for use.
You can install RVM using this method from any bash shell:
\curl -sSL https://get.rvm.io | bash -s stable
or update it to the most recent stable version by using:
rvm get stable
Once RVM is installed (or updated), you can install any Ruby version you choose, by doing the following:
rvm install 2.3.0
or upgrade from one version to another:
rvm upgrade 2.2.3 2.3.0
You can see which Ruby versions are installed by using this:
rvm list
You can also check to see which versions of Ruby that you can install on RVM by using this command:
rvm list known
Switch to a specific installed Ruby version by using the use command:
rvm use 2.3.0
and then switch back to an older version when you need to:
rvm use 2.2.3
Check out the RVM documentation for more features. You'll be surprised at how useful RVM actually is. There's a whole lot more to it than just what's shown here.
To upgrade your Ruby version using rbenv, you can use these steps. Some will only be necessary based on your environment. Plugins are an important aspect of this, if you have any installed.
Update rbenbv
First, you'll want to make sure that your rbenv version is updated. If you have the update plugin installed, you can update rbenv and all installed plugins using a single command:
rbenv update
Using the update plugin is highly recommended. However, if you are not using the update plugin, you can manually update rbenv in this way:
cd ~/.rbenv
git pull
Update plugins
If you have manually updated rbenv, you'll also need to update the plugins manually, as well. Make sure to follow the update instructions for each plugin.
One plugin that's very important to update at this point (if you have it installed) is the ruby-build plugin, which provides build support for Ruby under rbenv. This may improve the experience installing a new Ruby version in the next step.
Install Ruby version
After you have updated rbenv, you can install the new Ruby version:
rbenv install -v 2.3.0
Remove Ruby version
rbenv will allow you to manage and use multiple Ruby versions on a single machine. This is a huge benefit. However, if you no longer want the older Ruby version installed, you can remove it like this:
rbenv uninstall 2.2.3
Note that you can always re-install the Ruby version after uninstalling it, and use rbenv to manage the versions separately. This is good practice when working with multiple projects.

reinstall every gem for each ruby version?

I just installed Ruby 2.0.0 using rbenv and set it to the global ruby version for my system. Since 2.0 is compatible with 1.9.3, I tried to start up a Rails project with it, but got the following error. I did rbenv rehash after installing 2.0
The `rails' command exists in these Ruby versions:
1.9.3-p327
Does this mean that every gem I installed on my system with 1.9.3 has to be reinstalled if I wish to use it with 2.0?
As seen here:
You need to reinstall bundler for each version of Ruby you use. See Ruby versions where you have it installed:
rbenv whence bundle
See your current version:
rbenv version
Install bundler for that version, if missing:
gem install bundler
Yes. Rbenv (and RVM) have separate "gem home" directories for each installed version of Ruby. There may be ways to symlink certain directories to get them to share, but this will likely lead to problems, particularly with gems that include native C extensions, which may or may not compile and run cleanly in multiple versions.
If you have a Gemfile, easiest thing is to just bundle install again for Ruby 2.0, giving you duplicate copies of many gems and Ruby-2.0 compiled versions of any native gems.
Another solution to this is to copy (or reinstall) the gems from your previous version to the newly installed version. How to do that is answered in detail in this question, which has two scripts -- one to install from local cache, one to reinstall from the internet (mine).

Rails -- gem installation

Quick question about gem installation -- when I use bundle install I know it installs the gems necessary for my individual project, but it doesn't affect other projects on my computer. If I use gem install name_of_gem would that also only affect the current project or would it affect all projects on my computer using rails (a generic installation)? In general I think I am a little confused about how exactly gem installation works, so if your answer could include some general background information to help me understand this that would be great!
Yes, gems are typically installed system-wide, or in your home directory is this is not possible. By default, when your application uses a gem, RubyGems loads the latest installed version. If you want to use a specific version, RubyGems lets you do that with this syntax:
require 'rubygems'
gem 'RedCloth', '3.0'
Bundler is a helpful tool that tracks the versions of a gem that are being used to develop a project, and then allows you to both install them in one fell swoop with bundle install, and also to load those exact versions. The application loads them by loading the Bundler code, which overrides parts of RubyGems to use the versions specified in the Gemfile.
By default, Bundler just calls RubyGems to install gems (again, system-wide or in your homedir). You can ask it to store the gems in a directory called vendor/cache by using bundle package. This lets you "freeze" the gems so that you can distribute them with the source code.
If you want further isolation of your Ruby environments, you should use RVM, which lets you set up isolated gemsets, and in fact, different versions of Ruby, to use on different projects. When you're using RVM, the directory where RubyGems installs things is overridden and is specific to your current Ruby version and gemset.
I'd recommend reading the docs for both RubyGems and Bundler; they're both quite good.
When you do bundle install the gems are installed at rubygems and would be available for all your projects unless you're using RVM and setting up gemsets for your projects.
When you're not using RVM and you do a gem install your operating system is probably going to install the gem at your current user's files (usually ~/.gem), if you sudo install gem it's going to install wherever is the place your system Ruby is installed.
I would really recommend you to setup RVM do manage separate groups of gems and rubies. You can read their website linked above or a simple tutorial I wrote to use it.

How can I upgrade my Ruby Gems to the latest version "safely"?

Is there any way that I can upgrade my Ruby Gems, and if it doesn't work (on what I'm upgrading them for), than rollback the changes?
You need install rubygems in other directory of your previous version. After you can change all link to rubygems to this new version.
You can use too rvm. It's really simple and it's allways with latest rubygems. If you don't want it. just delete the .rvm directory.
Just upgrade RubyGems as normal, if it messes up, just download the last version and run sudo ruby setup.rb. http://rubygems.org/pages/download
If you do run into problems, the RubyGems team would love to hear about it: http://help.rubygems.org

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