There is NO install for mrfixit's debian, the install is a dd (to emmc)
To install to SD, use etcher, I assume you have another computer?
From this other computer, using etcher, unless you already have done it
Then boot it, set up user, don't bother upgrading at this point
Copy pinebookpro-debian-desktop-mrfixit-191123.img.xz (mrfixit debian) to Downloads
on SD card (/home/$USER/Downloads ($USER is whatever your login name is)
Then boot with SD inserted, lsblk and mount|grep mmc will tell which mmcblk is which
(/ is on SD card, partition 2, p2,,,,, boot on same card,, p1, emmc is obviously other mmcblk
this is if the SD card boots OK, first boot will ask for a user and password other than rock64 IIRR)
Then run commands above, will install mrfixit as OOTB (out of the box), just as
when you first got PBP (on emmc)
One way to be sure you have booted mrfixit is run uname -r ,,,, will either be 4.4.210 or 4.4.213
--edit--
> the Debian on the SD card fails to run a software upgrade
You are connected to internet??? ping google.com succeeds??
It is a manual process for debian, apt-get update, apt-get upgrade,, mrfixit's upgrade is a bit "iffy",,try again
Understand, there are 2 different upgrades, mrfixit and debian, mrfixit is the icon one
To install to SD, use etcher, I assume you have another computer?
From this other computer, using etcher, unless you already have done it
Then boot it, set up user, don't bother upgrading at this point
Copy pinebookpro-debian-desktop-mrfixit-191123.img.xz (mrfixit debian) to Downloads
on SD card (/home/$USER/Downloads ($USER is whatever your login name is)
Then boot with SD inserted, lsblk and mount|grep mmc will tell which mmcblk is which
(/ is on SD card, partition 2, p2,,,,, boot on same card,, p1, emmc is obviously other mmcblk
this is if the SD card boots OK, first boot will ask for a user and password other than rock64 IIRR)
Then run commands above, will install mrfixit as OOTB (out of the box), just as
when you first got PBP (on emmc)
One way to be sure you have booted mrfixit is run uname -r ,,,, will either be 4.4.210 or 4.4.213
--edit--
> the Debian on the SD card fails to run a software upgrade
You are connected to internet??? ping google.com succeeds??
It is a manual process for debian, apt-get update, apt-get upgrade,, mrfixit's upgrade is a bit "iffy",,try again
Understand, there are 2 different upgrades, mrfixit and debian, mrfixit is the icon one