Problems trying to install Chef 11.10.4

Chef Infra (archive)
1

Hi, i'm trying to download Chef 11, as our recipes/setup etc apparently doesn't work with Chef 12

I am running on OSX Yosemite

using the ominbus installer while specifying version

curl -L https://www.opscode.com/chef/install.sh | sudo bash -s -- -v 11.10.4-1

this all appears to download and install chef 11 but try to verify this with 'knife -v' i'm getting this error

/opt/chef/embedded/lib/ruby/site_ruby/1.9.1/rubygems/dependency.rb:247:in to_specs': Could not find chef (>= 0) amongst [] (Gem::LoadError) from /opt/chef/embedded/lib/ruby/site_ruby/1.9.1/rubygems/dependency.rb:256:in to_spec'
from /opt/chef/embedded/lib/ruby/site_ruby/1.9.1/rubygems.rb:1231:in gem' from /usr/bin/knife:22:in '

it's odd because when i check "ruby -v" it's telling me ruby is 2.0.0p481 and when i 'echo $GEM_PATH' it displays /Users/nathanmal/.gem/ruby/2.2.0:/Users/nathanmal/.rubies/ruby-2.2.0/lib/ruby/gems/2.2.0

so it seems there are multiple versions of ruby installed on my system, does anyone know how to clean this up and get chef server 11 up and running? thanks!

nathan