I'm having a big problem right now. My site is written in Ruby on Rails, and I'm using the active merchant gem to interface with PayPal. The site is hosted on heroku.
I have an API key and API signature set as config variables in my heroku app. However, I still get the error:
Running: rake assets:precompile
An API Certificate or API Signature is required to make requests to PayPal
(See full trace by running task with --trace)
I just found out about this command:
heroku labs:enable user-env-compile -a myapp
BUT it is experimental.