Yay, I figured it out! Here's my best attempt at an assessment of what was happening and then I'll follow with what I did to get it working the way I wanted it to. It seems that in fact the twitter-bootstrap-rails gem (henceforth referenced as twitter bootstrap) does have its own version of breadcrumbs and that in my local environment, a hybrid variety of breadcrumbs was being used between twitter bootstrap and the breadcrumbs_on_rails gem (henceforth referenced as breadcrumbs). So I was getting the nice twitter bootstrap styling for the breadcrumbs but also getting the additional helper methods provided with the breadcrumbs gem (like adding default breadcrumbs at the top of each form controller, outside of any methods).
It seems that in Heroku, however, the breadcrumbs gem was being used exclusively, meaning that I was getting the different, less desirable (to me), styling for the breadcrumbs, and also of course all of the helper methods.
So what I finally came to as a solution to get things working the way I wanted was to:
a) remove the breadcrumbs gem from my gemfile AND
b) move the twitter bootstrap gem out of the assets group and into the main flow of the gemfile
c) I also had to move the helper methods I had at the top of some of my form controllers to within the action methods on the form controllers. I was still able to be DRY about it by putting the common ones in a method that I could call from each action to which they applied, as in the following:
class WebDeveloperJobsController < ApplicationController
def index
@web_developer = WebDeveloper.singleton
@jobs = @web_developer.sorted_jobs
add_necessary_breadcrumbs
end
def show
@job = WebDeveloperJob.find(params[:id])
add_necessary_breadcrumbs
add_breadcrumb "Job", web_developer_job_path(@job)
end
def add_necessary_breadcrumbs
add_breadcrumb "Education", web_developer_trainings_path
add_breadcrumb "Projects", web_developer_projects_path
add_breadcrumb "Endorsements", web_developer_endorsements_path
add_breadcrumb "Videos", web_developer_videos_path
add_breadcrumb "Jobs", web_developer_jobs_path
end
end