when i’ve tried to install emulators from source for upto date versions,. most always fail at “/home/pi/RetroPie-setup/temp/build/Emulator/emulator not found (substitute “emulator” to what i try to build)
What did you start with as your base install? Raspbian?
The build must be failing further up, can you see anything if you scroll up? If not you can always run the build with logging and review the log afterwards.