ERROR “swiftc failed with exit code 1” when converting to latest syntax

Question

I was trying to convert syntax of old Swift project to new one as per few suggestion on Stack Overflow I tried converting it through Edit > Convert > To latest Synta

Answer 1

delete Derived Data folder and Build it.

Go to Xcode -> Preferences -> Locations for get the derived data path or cmd+Alt+shift+k

OR

Just remove inactive file(deleted file) from Build phases