Topic: Problem with Unicorn

I deployed my application in the local server and i'm using unicorn and nginx. I tried to run 'bundle exec unicorn_rails' but it is showing 'ERROR: Gem bundler is not installed, run `gem install bundler` first.'. even if I run gem install bundler the bundler getting installed, But it is showing the same error again i.e. Gem bundler is not installed, run `gem install bundler`.