Error starting application Your Rack app raised an exception when Pow tried to run it. Bundler::GemNotFound: Could not find ??? in any of the sources
Turns out that Pow doesn’t know anything about rbenv unless you tell it.
Thomas Fuchs tweeted a solution, suggesting that you just add the following to a
Kill off your Pow process (I use the Powder gem for this i.e.
powder down && powder up), and all should work just fine. I personally prefer the solution mentioned in this related Github ticket as is saves having to hardcode your home directory: