How to fix: RVM does not offer recent Ruby versions

If you want to switch to another ruby versions, you have several options, depending on what you want: Do you want to switch temporarily, per project, or globally?
Here is a short guide.

Unlike RVM, **rbenv does not offer a command like `rvm ...

When you run rake db:rollback and nothing happens, you are probably missing the latest migration file (or have not migrated yet).

$ rake db:rollback
$ 

If that happens to you, check your migration status.

$ rake db:migrate:status

...

tl;dr: Do not use merge! for session hashes. Use update instead.

Outline

Let's assume you're modifying the Rails session. For simplicity, let's also assume your session is empty when you start (same effect when there is data):

# In o...

When using git diff, you might encounter weird characters where umlauts (or any other UTF-8) characters should be. It looks like this:

R<C3><BC>ckg<C3><A4>ngig # should be "Rückgängig"

However, not Git is to blame [but the less comma...

On recent/fresh installations of Ruby 1.8.7 you may encounter this error why calling any bundled binary (or just bundle exec):

/home/arne/.rvm/gems/ruby-1.8.7-p374@global/gems/rubygems-bundler-1.4.2/lib/rubygems-bundler/noexec.rb:75:in ...

iPads will not trigger click events for all elements. You can fix that, but you don't want to know why.

Example: Capturing clicks on table rows (use case would be clicking the 1st link inside it for better UI). Consider this setup:

<table>

...

Every time I started RubyMine, it opened the main window on the left monitor -- when moving it to the center monitor and closing it, the next time it still opened up on the left one.

Here is how I forced RubyMine to start up on a different screen...

When you tell rbenv to install a Ruby it does not know about, you will get an error message.

$ rbenv install 2.1.2
ruby-build: definition not found: 2.1.2

You can list all available versions with `rbenv install --list'.

...

Add deprecation warnings and their solution or link to available solutions.

Global access to Rake DSL methods is deprecated. Please include Rake::DSL into classes and modules which use the Rake DSL methods.
---------------------------------------...

The gem json fails to install for Ruby 2.5 if you use a version equal or below 1.8.3.

Run bundle update json --conservative to solve this issue.

The backtrace you will encounter looks like this:

Building native extensions. This coul...