I just found a line on this page (https://arturbosch.github.io/detekt/howto-buildupondefaultconfig.html) that seems to have some more info:

Make sure to specify the 

input

 parameter or no sources are found and detekt won’t run!

This seems to be partially true. It does seem to run if you don't have a separate config YAML file. I updated the input as per that page and it works well enough for now. Still confusing that it can run without it in some scenarios.

@Bryan Lindsey thanks for noting down your troubleshooting process. May I ask you to submit a PR, if you have ideas on how to improve detekt's documentation?

Hi @schalkms. My interpretation of things is that the documentation is actually fine (the info was there on the page very much related to what I was looking at - I was just skimming it too fast which is why it took so long to figure out my error. However, the functionality maybe doesn't quite match the documentation, so perhaps there's a bug in the implementation? I can log an issue for it

Mhhm, I'm not sure. The documentation is quite old. Maybe @Artur Bosch can lend a helping hand here.

For what it's worth, I have it working fine now. It's mostly just a little confusing why it sorta seemed to work when the documentation implies it shouldn't have.