Same problem here! I've got a Mac Mini 2018 with 128gb, which had 17gb left but it still gave me that error message. I only use it for Xcode, so there isn't any random data, apart from a couple of images, which include a single wallpaper and small-ish test files.
I deleted a bunch of pre-installed apps(like Garage Band and iMovie - these were at least 5gb) and also a lot of simulators (no idea why they even existed) and two old iOS versions.
Now there are 40gb left but it still displays the same message!
I even installed DaisyDisk but there's nothing more I can delete without deleting Xcode itself! The download for Xcode 12.4 is only 11.6gb! This is ridiculous!
Topic:
Developer Tools & Services
SubTopic:
Xcode
Tags: