So I started fiddling about with a new Rails project and after finding a likely starting point, I immediately ended up with this:

Webpacker can't find application.js in

I'm old school Rails and I find the whole asset compilation situation, honestly, perplexing. The solution turned out to be:

bundle exec rails webpacker:install

after the normal:

git clone foo
bundle install
bundle exec rake db:migrate

I have no idea why the bundler install doesn't handle executing webpacker:install but cie la vie. The more things change, the more they stay the same …