.rvrmc / "Could not find railties" when cloning new Rails from github - ruby-on-rails

Question

I cloned a Rails app developed by another person within my company from Github.
When I cd into the app's directory I get this message in the terminal:
You are using '.rvmrc', it requires trusting, it is slower and it is not compatible with other ruby managers,
you can switch to '.ruby-version' using 'rvm rvmrc to [.]ruby-version'
or ignore this warning with 'rvm rvmrc warning ignore /Users/george/evil-genius/Loopadoop/.rvmrc',
'.rvmrc' will continue to be the default project file in RVM 1 and RVM 2,
to ignore the warning for all files run 'rvm rvmrc warning ignore all.rvmrcs'.
Then when I try to run any rails command e.g. rails server I get this error:
/Users/george/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/rubygems/dependency.rb:247:in `to_specs': Could not find railties (>= 0) amongst [rvm-1.11.3.8] (Gem::LoadError)
from /Users/george/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/rubygems/dependency.rb:256:in `to_spec'
from /Users/george/.rvm/rubies/ruby-1.9.3-p448/lib/ruby/1.9.1/rubygems.rb:1231:in `gem'
from /Users/george/.rvm/rubies/ruby-1.9.3-p448/bin/rails:22:in `<main>'
If I run rvm rvmrc to .ruby-version, I no longer get the "you are using '.rvmrc'..." warning, but I still get the same error message about railties when trying to run rails commands.
rvm list shows these versions of Ruby installed:
rvm rubies
* ruby-1.9.3-p385 [ x86_64 ]
=> ruby-1.9.3-p448 [ x86_64 ]
ruby-2.0.0-p195 [ x86_64 ]
ruby-2.0.0-p247 [ x86_64 ]
# => - current
# =* - current && default
# * - default
And my rvm version is 1.22.18.
What's happening? I don't understand rvm or .rvmrc files at all, and all other Rails stuff in other apps on my machine work perfectly fine. How can I get this rails app to work?
FWIW, here's what the .rvmrc file looks like when I first clone the repo from GH. (Comments removed for brevity):
#!/usr/bin/env zsh
environment_id="ruby-1.9.3-p448#loopAdoop"
if [[ -d "${rvm_path:-$HOME/.rvm}/environments"
&& -s "${rvm_path:-$HOME/.rvm}/environments/$environment_id" ]]
then
\. "${rvm_path:-$HOME/.rvm}/environments/$environment_id"
for __hook in "${rvm_path:-$HOME/.rvm}/hooks/after_use"*
do
if [[ -f "${__hook}" && -x "${__hook}" && -s "${__hook}" ]]
then \. "${__hook}" || true
fi
done
unset __hook
if (( ${rvm_use_flag:=1} >= 2 )) # display only when forced
then
if [[ $- == *i* ]] # check for interactive shells
then printf "%b" "Using: \E[32m$GEM_HOME\E[0m
" # show the user the ruby and gemset they are using in green
else printf "%b" "Using: $GEM_HOME
" # don't use colors in non-interactive shells
fi
fi
else
rvm --create "$environment_id" || {
echo "Failed to create RVM environment '${environment_id}'."
return 1
}
fi
And after I run rvm rvmrc to .ruby-version, the .rvmrc file is deleted, and two new files are generated: .ruby-gemset, which just contains the name of my app, and .ruby-version, which just contains the text "ruby-1.9.3-p448"

Answer 1

you need to run:
gem install bundler &&
bundle install
it will install the gems needed for this project
you can make it automated on cd with:
echo rvm_autoinstall_bundler_flag=1 >> ~/.rvmrc