I have a brand new 2020 Mac mini (Intel i3 quad core chip). My install (dedicated Ubuntu NO dual boot) fails with the famous;
Executing 'grub-install /dev/nvme0n1' failed. This is a fatal error.
I have bypassed the T2 chip by booting into recovery mode and selecting "No Security" and "Allow booting from external drive". So when I turn on the Mac mini and hit the Alt key it shows me the two icons to select boot, the hard drive and the flash drive. My flash drive has the ubuntu-20.04-desktop-amd64.iso that has been made into a bootable USB by the startup disk creator on my working Ubuntu 14.04 LTS laptop.
No matter what I do the install fails and the Mac mini subsequently boots into an old Grub 2.04 with limited capabilities.
I am unable to follow this good advice Install ubuntu 18.04 on mac mini 2018 as I cannot install rEFInd in that manner.
I have tried several of the Matt Gadient (legend) bootable iso versions.
I have reformatted the entire drive as gpt using gparted and basically started from scratch but cannot find any partition combination that will let the installer complete (other than forcing it to install when there is no EFI partition in which case the installer does NOT fail but obviously the Mac mini fails to boot to anything).
I have tried several manual grub-install options from these pages but the most common error then is /cow is busy and it cannot be unmounted.
When I boot up with boot-repair the program runs but it does not detect anything. From that program if I terminal and lsblk it does not even show the nvme0n1 drive.
So, any ideas how I can get the installer to work or how I can manually install a grub?