Macos Catalina Iso |best| -

softwareupdate --fetch-full-installer --full-installer-version 10.15.7 From the official installer, you can create a clean ISO:

# Create a blank disk image hdiutil create -o /tmp/Catalina -size 8500m -volname Catalina -layout SPUD -fs HFS+J hdiutil attach /tmp/Catalina.dmg -noverify -mountpoint /Volumes/Catalina Write the installer to the image (adjust path to your installer) sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Catalina --nointeraction Unmount and convert to ISO hdiutil detach /Volumes/Install\ macOS\ Catalina hdiutil convert /tmp/Catalina.dmg -format UDTO -o ~/Desktop/Catalina.iso macos catalina iso