I have no idea what to do at this point. Is there a guide or something to help me troubleshoot this? I also don’t mind too much if there’s no fix except to wipe it and start over.
Can you boot from a live-USB? If that boots, you may need to repair your OS with it. That last line seems to indicate that the UUID of the drive it expects to be there isn’t showing up. Might be lucky enough to just reseat it and it will start working.
Seeing if you can get to the recovery partition. Reboot, immediately at Framework splash screen tap F12 repeatedly, see if you are able to locate “Pop!_OS Recovery” - arrow down to it, enter key.
If this is not possible, short of repairing the install, I’d reinstall.
I agree with Curtis, UUID of the drive appears to be gone. So this may require some testing against a live USB as well. See if the drive mounts from a live environment, etc.
Just to add to what Matt said about the recovery partition, there’s also further documentation available for that here: Repair the Bootloader - System76 Support
mdadm issues usually point to a device manager used for software raid. Apparently it is missing the drives or has a corrupted configuration file.
I’d go in on the command line to check for the issues, but remotely that is a real pita.
As hinted by others, try to boot the recovery partition and see if you can fix it there.
Thankfully, there wasn’t anything important on that Pop_OS! installation, so I’ve decided to just wipe it and take the opportunity to try out a different distro. Thanks!