Guide doesn't work with latest version of sinatra-asset-pipeline

[DSUK]

Recreate:
download this example
bundle update sinatra-asset-pipeline
bundle exec rackup -p 3000

[hut8]

Please include the error message

[DSUK]

The CSS gives a 404, causing the page to load without bootstrap.

I have realised it might be something to do with the stylesheet_tag given that pre-update it generates something along the lines of:
<link rel="stylesheet" href="/assets/application-0d1704d2469e1a168960ab2a81f0904f.css">
and after updating you get:
<link rel="stylesheet" href="/stylesheets/application.css">