postmarketos-base.post-install failed to write /etc/fstab

Wifi and modem completely disappeared from ifconfig for me and I lost all connectivity after rebooting following this upgrade (please note I ran fix on linux-postmarketos-allwinner due to the depmod warnings in the previous run): Now we know that /boot not being mounted properly which broke the mkinitramfs upgrade, makes sense I suppose. Here is the output of the upgrade failing as a result:

$ sudo apk upgrade
(1/20) Upgrading busybox (1.31.1-r21 -> 1.32.0-r0)
Executing busybox-1.32.0-r0.post-upgrade
(2/20) Upgrading ssl_client (1.31.1-r21 -> 1.32.0-r0)
(3/20) Upgrading busybox-suid (1.31.1-r21 -> 1.32.0-r0)
(4/20) Upgrading lxc-libs (4.0.2-r0 -> 4.0.3-r0)
(5/20) Upgrading busybox-extras (1.31.1-r21 -> 1.32.0-r0)
(6/20) Upgrading nuspell (3.1.1-r0 -> 3.1.2-r0)
(7/20) Upgrading tslib (1.21-r0 -> 1.22-r0)
(8/20) Upgrading libcurl (7.71.0-r1 -> 7.71.1-r0)
(9/20) Upgrading sudo (1.9.0-r0 -> 1.9.1-r0)
(10/20) Upgrading mozjs68 (68.9.0-r0 -> 68.10.0-r0)
(11/20) Upgrading osk-sdl (0.55-r0 -> 0.56-r0)
(12/20) Upgrading phoc (0.1.9-r0 -> 0.4.0-r0)
(13/20) Upgrading phosh (0.3.1-r0 -> 0.4.0-r0)
(14/20) Upgrading linux-postmarketos-allwinner (5.6.0_git20200528-r1 -> 5.7.0_git20200629-r0)
(15/20) Upgrading fail2ban (0.11.1-r1 -> 0.11.1-r2)
(16/20) Upgrading fail2ban-openrc (0.11.1-r1 -> 0.11.1-r2)
(17/20) Upgrading firefox (77.0.1-r4 -> 78.0.1-r0)
(18/20) Upgrading curl (7.71.0-r1 -> 7.71.1-r0)
(19/20) Upgrading exiv2 (0.27.2-r6 -> 0.27.3-r0)
(20/20) Upgrading telegram-desktop (2.1.14-r0 -> 2.1.16-r0)
Executing busybox-1.32.0-r0.trigger
Executing glib-2.64.3-r1.trigger
Executing gtk-update-icon-cache-2.24.32-r2.trigger
Executing kmod-27-r0.trigger
depmod: WARNING: could not open modules.order at /lib/modules/5.6.0: No such file or directory
depmod: WARNING: could not open modules.builtin at /lib/modules/5.6.0: No such file or directory
Executing desktop-file-utils-0.26-r0.trigger
Executing postmarketos-mkinitfs-0.12.2-r0.trigger
==> initramfs: creating /boot/initramfs-postmarketos-allwinner
Scanning kernel module dependencies...
NOTE: ** modprobe warnings below can be ignored ** if your device does not run the
mainline kernel yet (most devices!) or if the related kernel options are enabled
with 'y' instead of 'm' (module).
 - deviceinfo: sun6i_mipi_dsi sun4i_drm pwm_sun4i sun8i_mixer
 - 00-default.modules: dm_crypt ext4 usb_f_rndis
==> kernel: device-tree blob operations
==> kernel: copying dtb allwinner/sun50i-a64-pinephone-1.1 to boot partition
==> initramfs: creating uInitrd
Image Name:   uInitrd
Created:      Thu Jul  2 19:38:52 2020
Image Type:   AArch64 Linux RAMDisk Image (uncompressed)
Data Size:    1436197 Bytes = 1402.54 KiB = 1.37 MiB
Load Address: 00000000
Entry Point:  00000000
==> kernel: creating uImage
Image Name:   postmarketos
Created:      Thu Jul  2 19:38:52 2020
Image Type:   AArch64 Linux Kernel Image (uncompressed)
Data Size:    16435208 Bytes = 16050.01 KiB = 15.67 MiB
Load Address: 80008000
Entry Point:  80008000
==> initramfs: creating /boot/initramfs-postmarketos-allwinner-extra
Executing postmarketos-base-3-r34.trigger
Configuring a getty on port ttyS0 with baud rate 115200
OK: 2750 MiB in 686 packages
cyberphone:~$ sudo apk fix linux-postmarketos-allwinner
[sudo] password for user: 
(1/1) Reinstalling linux-postmarketos-allwinner (5.7.0_git20200629-r0)
Executing busybox-1.32.0-r0.trigger
Executing kmod-27-r0.trigger
Executing postmarketos-mkinitfs-0.12.2-r0.trigger
==> initramfs: creating /boot/initramfs-postmarketos-allwinner
Scanning kernel module dependencies...
NOTE: ** modprobe warnings below can be ignored ** if your device does not run the
mainline kernel yet (most devices!) or if the related kernel options are enabled
with 'y' instead of 'm' (module).
 - deviceinfo: sun6i_mipi_dsi sun4i_drm pwm_sun4i sun8i_mixer
 - 00-default.modules: dm_crypt ext4 usb_f_rndis
==> kernel: device-tree blob operations
==> kernel: copying dtb allwinner/sun50i-a64-pinephone-1.1 to boot partition
==> initramfs: creating uInitrd
Image Name:   uInitrd
Created:      Thu Jul  2 19:39:54 2020
Image Type:   AArch64 Linux RAMDisk Image (uncompressed)
Data Size:    1436231 Bytes = 1402.57 KiB = 1.37 MiB
Load Address: 00000000
Entry Point:  00000000
==> kernel: creating uImage
Image Name:   postmarketos
Created:      Thu Jul  2 19:39:54 2020
Image Type:   AArch64 Linux Kernel Image (uncompressed)
Data Size:    16435208 Bytes = 16050.01 KiB = 15.67 MiB
Load Address: 80008000
Entry Point:  80008000
==> initramfs: creating /boot/initramfs-postmarketos-allwinner-extra
OK: 2750 MiB in 686 packages
$

The devices that still show up in ifconfig are: lo, and usb0

If anyone knows how to possibly re-enable wifi or the modem, that would be useful in actually allowing me to upgrade out of this state again! Or is it possible to somehow connect from a desktop PC to it via USB? I never tried that so far. got usb ssh to work, so that should allow me to copy packages to the device to fix it once somebody knows what to do