When using a bblayers.conf like the one below, yocto-kernel won't find my bsp layer. Building a image works just fine.

LCONF_VERSION = "6"

BBPATH = "${TOPDIR}"
BBFILES ?= ""

BBLAYERS ?= " \
  /home/stefans/yocto/poky/meta \
  /home/stefans/yocto/poky/meta-yocto \
  /home/stefans/yocto/poky/meta-yocto-bsp \
  "
BBLAYERS_NON_REMOVABLE ?= " \
  /home/stefans/yocto/poky/meta \
  /home/stefans/yocto/poky/meta-yocto \
  "

BBLAYERS += "/home/stefans/yocto/builds/yotta/meta-myqemu"


# yocto-kernel config list myqemu
Unable to find the BSP layer for machine myqemu.
Please make sure it is listed in bblayers.conf


Removing the last line and adding the layer like this

BBLAYERS ?= " \
  /home/stefans/yocto/poky/meta \
  /home/stefans/yocto/poky/meta-yocto \
  /home/stefans/yocto/poky/meta-yocto-bsp \
  /home/stefans/yocto/builds/yotta/meta-myqemu \
  "

solves the problem.