Running a modular Sinatra app on Heroku

Hello, I'm having trouble getting a modular Sinatra app to run correctly in production. The git push heroku master works fine, but when I try to submit a form through the /contact page I get:

bundler: failed to load command: rackup (/app/vendor/bundle/ruby/2.4.0/bin/rackup).

My Procfile:

web: bundle exec rackup config.ru -p $PORT

My config.ru:

require 'rubygems'
require 'bundler'

Bundler.require

require_relative 'lib/app'
run Tir::App

My lib/app.rb:

require 'sinatra/base'
require File.expand_path('articles', File.dirname(__FILE__))
require File.expand_path('static', File.dirname(__FILE__))
require File.expand_path('landing', File.dirname(__FILE__))

module Tir
  class App < Sinatra::Base
    #code
  end
end 

I've tried all manner of tweaks but am stuck! Thanks for any help.

Comments

[fullstackplus]

Hi Alex,

thanks for the reply. I'm assuming your example above is for a classic-style (not subclassed) Sinatra app? Mine is subclassed / modular, so I'm pretty much following the recipe outlined here: oreilly.com/library/view/sinatra-u...

I might give a classic-style version a try though, if only for debugging purposes. Cheers!