how to create a bootable Catalina installer drive with latest patch?

[fully_wong]

Folks,

Have you found that macOS Big Sur or Monterey is not such friendly for those devices carries a Intel-dual-core-CPU and 8 GB memory? 

For those devices, we recommend using macOS Catalina 10.15.7. So how can we create a bootable Catalina installer drive with latest patch?

[sdagley]

@fully_wong You can't create a bootable installer with a fully patched version of Catalina 10.15.7, but you can use AutoDMG to create a disk image of a fully updated 10.15.7 install (specifically you'll need AutoDMG v1.10b587) and MacProvisioner 4.2 to create a provisioning disk which can be mounted by a Mac booted into Recovery Mode and the Mac Provisioner script run to install the AutoDMG created image.

Note: I haven't tested it since the Mac Provisioner 4.0 release, but I do not believe you can directly downgrade a Mac running Big Sur or Monterey to Catalina with this mechanism, but will have to boot from a Catalina 10.15.7 Build 19H15 installer drive to run the provisioning script.

[mickgrant]

open terminal and type

sudo softwareupdate --list-full-installers

This should list out all available full installers.
select the one you want and type

sudo softwareupdate --fetch-full-installer -full-installer-version <version number goes here>

This will download the installer to your Applications folder

To make the installer bootable, use this command

sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSBDrive

This will then prompt you that the USB will be wiped, and then it will proceed to install the bootable installer.

[sdagley]

@mickgrant The latest available Install macOS Catalina.app is for 10.15.7 Build 19H15. If you install that you'd then need to install Security Update 2022-003 (Catalina) to update to the latest version Build 19H1824.