2) look for config-5.15.6<something> file and nano into it. That's the config for the kernel that Ubuntu used for building it.
3) ctrl+w and type or paste "CONFIG_UBSAN_TRAP" and hit enter. (paste is ctrl+shift+v)
If it doesn't find it, then it is odd that it doesn't work for you. The problem could be elsewhere. That said I don't have that kernel version running.
1) Do an $ ls -lah /boot
2) look for config- 5.15.6< something> file and nano into it. That's the config for the kernel that Ubuntu used for building it.
3) ctrl+w and type or paste "CONFIG_UBSAN_TRAP" and hit enter. (paste is ctrl+shift+v)
If it doesn't find it, then it is odd that it doesn't work for you. The problem could be elsewhere. That said I don't have that kernel version running.