hdiutil convert /tmp/Catalina.dmg -format UDTO -o ~/Desktop/macOS_Catalina_10.15.7.iso
hdiutil detach /Volumes/Install\ macOS\ Catalina macos catalina 10157 iso download new
sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Catalina --nointeraction This takes 10-15 minutes. This is the critical step where Apple’s tool builds the bootable recovery system inside your DMG. hdiutil convert /tmp/Catalina
mv ~/Desktop/macOS_Catalina_10.15.7.iso.cdr ~/Desktop/macOS_Catalina_10.15.7.iso macos catalina 10157 iso download new