How One Bad Download Corrupted a 5-month Project

I'm pretty sure you shouldn't be mixing laptop OS's and phone OS's, but here we are. This "bad download" was mainly due to trying to install UIKit onto my macOS project. The problem? UIKit doesn't exist in macOs; the equivalent is AppKit. I tried to force-download (or more accurately, try and do a -Wl... terminal command), and restarted my computer. It booted up perfectly fine, but when I opened the file... BAM! The dreaded error: linker command failed with exit code 1 (use -v to see invocation) popped up, not to mention the Canvas/Preview wasn't there. So remember (you probably already know this but...), please never try forcing UIKit to macOS; there's something called AppKit.