genkernel does not check if /boot is mounted. If should do it, because, else kernel and initrd goes to wrong place Reproducible: Always Steps to Reproduce: 1. 2. 3.
Would not these normally already be mounted on a normal system, and /boot is not always an independent partition either. If you intend to let /boot be on an own partition, it should be the users own responsibility that it is mounted. You could also have migrated away from having /boot on it's partition and set the entry to noauto in /etc/fstab
genkernel does check if /boot is mounted; check genkernel.conf and ensure MOUNTBOOT is on.