Ruby, Rails 3.1, and the dreaded “Could not find a JavaScript runtime” error

  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 40.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 41.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 42.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 43.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 44.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 45.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 46.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 47.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 48.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 49.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 50.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 51.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 56.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 57.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 58.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 59.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 60.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 61.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 62.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 63.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 64.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 65.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 66.
  • warning: date() [function.date]: It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'America/Denver' for 'MDT/-6.0/DST' instead in /home/lyniqne/public_html/planetcakephp.org/drupal/sites/all/modules/token/token_node.inc on line 67.
Submitted by Derick Ng on 7 September 2011 - 2:53am

While deploying a custom Rails 3.1 application I came across the following error.

Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes.

The fix was simple.
Add these gems to your application Gemfile

gem 'execjs'
gem 'therubyracer'

And run bundler.

$ bundle install