How to stop Chrome fetching localhost over https

Whilst developing Jekyll sites locally, the Chrome browser will sometimes try to fetch the page over https, rather than http. This is problematic, because the browser just renders a protocol error:

This is caused by a security policy HSTS, or HTTP Strict Transport Security. We have to tell Chrome to forget that it wants to fetch localhost over a secure connection. To do this, visit chrome://net-internals/#hsts and find the field called Delete domain security policies. Enter localhost:4000 (or whatever address you are using for the local jekyll server) and click delete. Chrome will now fetch the site over http again.

Once again, I am grateful to the responses over at Stack Overflow. If this doesn’t fix your problem then that’s the next place you should look.