I did an update / upgrade cycle on my Mint box and I could still open a project and schematic in KiCad-nightly. So I can’t reproduce it.
paul@cezanne:~$ sudo apt upgrade
Reading package lists… Done
…
Need to get 466 MB of archives.
After this operation, 185 kB disk space will be freed.
Do you want to continue? [Y/n]
Get:1 Triple - Mirrors una/upstream amd64 firefox amd64 107.0.1+linuxmint1+una [63,7 MB]
Get:2 Index of /kicad/kicad-dev-nightly/ubuntu focal/main amd64 kicad-nightly-footprints all 202212021916+1ee260211~14~ubuntu20.04.1 [23,1 MB]
Get:3 Index of /kicad/kicad-dev-nightly/ubuntu focal/main amd64 kicad-nightly-packages3d all 202212012119+248c290e~13~ubuntu20.04.1 [378 MB]
Get:4 Triple - Mirrors una/upstream amd64 firefox-locale-en amd64 107.0.1+linuxmint1+una [735 kB]
Upgrading the distro works fine (I always update my Fedora versions from one to the next, and have some that have been upgraded all the way from Fedora 32/33 till now).
What happened is an underlying library that KiCad uses (wxWidgets) changed how it was built. That change necessitated a change in a build option for KiCad. The official package fix was coordinated by the Fedora packager of the wxWidgets library, and so KiCad was updated alongside that change to make everything work seamlessly. The nightly is built differently from the official package, and the change couldn’t be made to that until the actual official package and updated library had been released to users. The nightly build maintainer worked on integrating the required change yesterday, so the new build had the fix.