I've been following along with a tutorial for a Rails app. The tutorial is based on Rails 5 and I am using Rails 5.1.2. Everything works great locally and pushed to heroku with no problems. However, when I went to create an admin user on the production database by running:
$ heroku run rails c
it returns the following error:
/activesupport-5.1.3/lib/active_support/dependencies.rb:292:in `require': cannot load such file -- rack/handler/c (LoadError) from
/activesupport-5.1.3/lib/active_support/dependencies.rb:292:in `block in require' from
/activesupport-5.1.3/lib/active_support/dependencies.rb:258:in `load_dependency' from
/activesupport-5.1.3/lib/active_support/dependencies.rb:292:in `require' from
/rack-2.0.3/lib/rack/handler.rb:74:in `try_require' from
/rack-2.0.3/lib/rack/handler.rb:16:in `get' from
/rack-2.0.3/lib/rack/server.rb:301:in `server' from
/railties-5.1.3/lib/rails/commands/server/server_command.rb:68:in `print_boot_information' from
/railties-5.1.3/lib/rails/commands/server/server_command.rb:38:in `start' from
/railties-5.1.3/lib/rails/commands/server/server_command.rb:131:in `block in perform' from
/railties-5.1.3/lib/rails/commands/server/server_command.rb:126:in `tap' from
/railties-5.1.3/lib/rails/commands/server/server_command.rb:126:in `perform' from
/thor-0.20.0/lib/thor/command.rb:27:in `run' from
/thor-0.20.0/lib/thor/invocation.rb:126:in `invoke_command' from
/thor-0.20.0/lib/thor.rb:387:in `dispatch' from
/railties-5.1.3/lib/rails/command/base.rb:63:in `perform' from
/railties-5.1.3/lib/rails/command.rb:44:in `invoke' from
/railties-5.1.3/lib/rails/commands.rb:16:in `<top (required)>' from bin/rails:9:in `require' from bin/rails:9:in `<main>'`
To get around this I can run:
$ heroku run bash
$ rails c
and this allows me to update the production database. While this works and gets me what I need. I want to know why the original command doesn't work. I have searched everywhere for an answer and can't come up with anything that applies to me. I am trying to improve my developing skills and would like to understand why the original problem won't work.
I can add any files anyone needs to see, but I don't even know which ones would be relevant to this problem.
You can specify the name of the app in case you have several:
heroku run rails c -a APP_NAME