@darkcyberman You could be missing dependencies; compare your kernel with GENERIC, LINT, & NOTES.
There is "/boot/kernel.old/kernel" to boot previous kernel (would be useful only if that was the working version & had not installed your non-working version more than once). It can be loaded during boot (do not remember the process).
If you are using #ZFS on root, you may have the option to choose previous "#BootEnvironment" -- option is available from the boot menu.
...
2- not putting everything of "/var" under "zroot/var" dataset (with "canmount=on" of course)?
One of the reasons offered, on IRC, was that other datasets would cause churn in boot environment.
-- so does installation|upgrade of packages in boot environment.
#FreeBSD #var_strewn_about #bootEnvironment #boot_env
3/4
...
- 5 datasets & related mountpoints as children of "zroot/var" dataset (mounted under "/var" as expected; https://wiki.freebsd.org/BootEnvironments#Pool_Layout.2FDesign ).
(Observe different source datasets yourself if installed with ZFS options as mentioned: df -h /var/* | sort -u )
❔What is the justification for ...
1- putting some parts of "/var" in a root directory (boot environment);
zectl ZFS Boot Environment Manager for Linux https://hackeroo.co/344093
ax6761
not Evander Sinque
Wolfgang
VArchS
Hackeroo.co