ruby - Using Launchy gem gives an error -

i tried using launchy gem open browser in cli app. following error message.

  xprop: unable open display ''    /usr/local/rvm/gems/ruby-2.3.1/gems/launchy-2.4.3/lib/launchy/applications/browser.rb:63:in `browser_cmdline': unable find browser command. if th   is unexpected, please rerun environment variable launchy_debug=true or '-d' commandline option , file bug @ https://github.com/copiou   sfreetime/launchy/issues/new (launchy::commandnotfounderror)    /usr/local/rvm/gems/ruby-2.3.1/gems/launchy-2.4.3/lib/launchy/applications/browser.rb:67:in `cmd_and_args'    /usr/local/rvm/gems/ruby-2.3.1/gems/launchy-2.4.3/lib/launchy/applications/browser.rb:78:in `open'    /usr/local/rvm/gems/ruby-2.3.1/gems/launchy-2.4.3/lib/launchy.rb:29:in `open'    /home/himachhag-45739/code/popular-deals-from-slickdeals.net-cli/lib/popular_deals/cli.rb:49:in `open_deal_in_browser'    /home/himachhag-45739/code/popular-deals-from-slickdeals.net-cli/lib/popular_deals/cli.rb:36:in `menu'    /home/himachhag-45739/code/popular-deals-from-slickdeals.net-cli/lib/popular_deals/cli.rb:8:in `call'    ./bin/popular-deals:10:in `<main>' 

does know possible solution?