How can I get Syntastic to recognize newer Ruby syntax?

I'm using Syntastic in Vim, and it highlights newer Ruby syntax as errors. For example, if I use required keyword arguments (introduced in Ruby 2.1), like this:

def distance(from:, to:)
  # whatever
end

... it highlights the definition line and says "unexpected ','".

How can I get it to recognize this as valid Ruby syntax? I've already updated ~/.vim/syntax/ruby.vim.

Solution 1:

Specify the ruby executable for Syntastic

Syntastic calls ruby -c to check the syntax of a file, so the errors it shows depends on which version of ruby its using.

You can point it to the one you want to use like this:

let g:syntastic_ruby_exec = 'path/to/ruby/executable'

NOTE: on newer versions of Syntastic:

let g:syntastic_ruby_mri_exec = 'path/to/ruby/executable'

$ type ruby will tell you where your current Ruby executable is. Ruby installers have their own conventions about where they place their binaries. Eg:

• ruby-install puts ruby installations in ~/.rubies and specific versions at paths like ~/.rubies/ruby-2.2.0/bin/ruby
• RVM puts ruby installations in ~/.rvm/rubies and specific versions at paths like ~/.rvm/rubies/ruby-2.2.0/bin/ruby

Solution 2:

Using terminal macvim I also had this problem, which was compounded by the fact that I was using zsh, which for some reason was not respecting the rvm binary I gave syntastic. I realized that my paths where incorrect when running !echo $PATH in terminal macvim, I had several system paths appended to the top that were not in my regular shell still causing the default MRI to load.

To fix this, I did not need to specify the syntax checker at all in my .vimrc, however I had to update how zsh started. Using the thread at: http://vim.1045645.n5.nabble.com/MacVim-and-PATH-td3388705.html I ended up simply running sudo mv /etc/zshenv /etc/zprofile and now everything works and my paths are correct in mvim. This should also solve the problem of updating syntastic when installing a new ruby version via rvm.