Even Mojave has some supplemental update and security update.
After a few months I itch to upgrade again.
No surprise, the Catalina patch still won't go through the second phase.
Every time I do this I do this in a feverish pace and in the end, I don't know what I am doing.
But I have to say I am calm and a little bit more prepared. When it failed to boot up to continue the second phase. I was able to recover from the Mojave recovery snapshot though I forgot the details. But it certainly emboldened me to go really to Catalina instead of just going update Mojave as I know initially I was able to upgrade to Catalina but somehow in subsequent update I wasn't able to complete.
No surprise I wasn't able to go to the second phase of the patch to complete but then it didn't destroy the last bootable OS I was able to boot back holding the Alt or Option key.
So here are the steps
Download the latest Catalina patch from dosdude1
Make the USB drive
Boot from the USB drive (for me I have to switch back to the supported GPU card, otherwise I can't do this ALT boot sequence)
The installation reboot and back to the USB installation screen and in some instances it gives me the mouse setup, just click Next or similar to back out
Reboot holding down Alt key, you should see the Install partition of whatever it's properly called, you should see the USB and other possible Boot EFI from previous failed upgrades but pick the installation thingy you've never seen before that was just created in the first phase of the update
This should complete the second part of the installation.
Once it reboots you should be home free
Good luck.
PS: you won't be able to stream Netflix on Safari, but Chrome is perfectly fine.
