Flask-Assets working locally but not on Heroku

I'm working to modify a cookiecutter Flask app. I'm working locally on WIN7 and attempting to deploy to heroku. I'm currently trying to add a datepicker to a page. I've found https://eonasdan.github.io/bootstrap-datetimepicker/. The structure of myflaskapp:

I've set up bower to install the front end dependencies under the static root by using a .bowerrc file in the document root containing:

{ "directory" : "myflaskapp/static/bower_components" }

This cookiecutter uses flask-assets to manage the project assets. Following https://adambard.com/blog/fresh-flask-setup/ I've modified myflaskapp/assets.py file :

from flask_assets import Bundle, Environment
import os

css = Bundle(
    "libs/bootstrap/dist/css/spacelab/bootstrap.css",
    "bower_components/eonasdan-bootstrap-datetimepicker/build/css/bootstrap-datetimepicker.css",
    "css/style.css",
    "css/home.css",
    # "css/style.css",
    filters="cssmin",
    output="public/css/common.css"
)

js = Bundle(
    "libs/jQuery/dist/jquery.js",
    "libs/bootstrap/dist/js/bootstrap.js",
    "bower_components/moment/moment.js",
    "bower_components/eonasdan-bootstrap-datetimepicker/build/js/bootstrap-datetimepicker.min.js",
    "js/plugins.js",
    filters='jsmin',
    output="public/js/common.js"
)


assets = Environment()

assets.register("js_all", js)
assets.register("css_all", css)

myflaskapp/app.py initializes the assets:

from flask import Flask, render_template
from myflaskapp.assets import assets
    """
    :param config_object: The configuration object to use.
    """
    app = Flask(__name__)
    app.config.from_object(config_object)
    register_extensions(app)
    register_blueprints(app)
    register_errorhandlers(app)
    return app

def register_extensions(app):
    assets.init_app(app)

def register_blueprints(app):
    app.register_blueprint(public.blueprint)
    app.register_blueprint(user.blueprint)

In the myflaskapp/settings.py , during testing, I have set:

ASSETS_DEBUG = True  # Don't bundle/minify static assets

Locally, there are no errors in the console. On heroku , I get an Internal server error. Logs:

    ←[33m2016-03-19T18:02:12.464159+00:00 app[web.1]:←[0m     for org, cnt in self.resolve_contents(ctx):
    ←[33m2016-03-19T18:02:12.464161+00:00 app[web.1]:←[0m     raise BundleError(e)
    ←[33m2016-03-19T18:02:12.464162+00:00 app[web.1]:←[0m BundleError: 'bower_components/eonasdan-bootstrap-datetimepicker/build/css/bootstrap-datetimepicker.css' not found in load path:
    ['/app/myflaskapp/static']
    ←[33m2016-03-19T18:02:12.464150+00:00 app[web.1]:←[0m     rv = template.render(context)
    ←[33m2016-03-19T18:02:12.464151+00:00 app[web.1]:←[0m   File "/app/.heroku/python/lib/python2.7/site-packages/jinja2/environment.py", line 969, in render
    ←[33m2016-03-19T18:02:12.464152+00:00 app[web.1]:←[0m   File "/app/.heroku/python/lib/python2.7/site-packages/jinja2/environment.py", line 742, in handle_exception
    ←[33m2016-03-19T18:02:12.464154+00:00 app[web.1]:←[0m     {% extends "layout.html" %}
    ←[33m2016-03-19T18:02:12.464157+00:00 app[web.1]:←[0m     urls = bundle.urls()
    ←[33m2016-03-19T18:02:12.464153+00:00 app[web.1]:←[0m     reraise(exc_type, exc_value, tb)

As you can see in the top screenshot it is there. How can I fix this?

Note: I've been looking at https://github.com/mitsuhiko/flask/issues/348, which may have a bearing on this.

Try checking your .gitignore, build is often ignored which would exclude your static files here: bower_components/eonasdan-bootstrap-datetimepicker/build/*