Here's what helps: In the Apple Manu, go to About this Mac > Storage > Manage > Developer (nice little Easter egg hunt, well done Apple!) Look for older iOS variation you don't need, those can easily take up a good number of GBs There are also big size options "Xcode Caches" and "Project Build Data and Indexes", though I'm not sure how much trouble might be caused by deleting those Lastly, uninstall Xcode before installing a newer version There also is a free ("suggested tip-ware") app named DevCleaner which essentially appears to look for the same files as described above Some more proactivity on Apple's part on this would certainly be useful though. To just leave a user with a "Not enough disk space" error message upon trying to update Xcode when there are dozens of available GBs on the drive is not exactly helpful.

Same here, I seem to have that problem * every single time * Xcode gets updated - right now I have 34 GB available on my HD, and Appstore says that the Xcode 12.3 update needs 11.6 GB - yet when I tried to install, I get "Not enough disk space". I reckon there is some decompression of downloaded files going on, but 34+ GB available space not enough disk space is a ludicrous management of resources on Apple's part. I guess my only option is to uninstall Xcode first and then re-install the latest version from scratch. Apple, you guys are the experts - this is the best you can come up with..??? What a shame.

Thank you for that link, that should do the trick! (I still wonder exactly what Mac Catalyst is - https://developer.apple.com/mac-catalyst shows an app icon, but I don't find a specific tool with that name. Is it a concept (and related functionality integrated into Xcode)..? Am I the only one who finds that confusing..?)

I went back into the assets catalog, and finally I discovered the extra icons needed for Mac after some more scrolling. Of course Xcode didn't bother to tell me about it - neither upon adding a Mac version to an iOS app nor during "validation" in Xcode or upon Archiving. I wonder if anyone at Apple ever checked went through that process themselves... the easiest things are frustrating problems, extremely unnecessarily so.

I'm seeing a very similar issue with my only (free, no ads) app which generates 0-5 daily downloads on average. There are mysterious download spikes all the way to 500 on a single day - all those downloads happened in Germany though (my app supports EN and DE). Every such spike is a clean n*100 downloads. Apple, I think you really need to get to the bottom of this! Evidently there are more apps out there affected by manipulated download spikes.