bbappend files and "ERROR: no recipes available for"

[Markus Svilans <msvilans@aeonyx.ca>]

Dear list,

I am working on a compact filesystem image, that contains firmware only 
for the network hardware on the motherboard.

Therefore, I created a linux-firmware.bbappend file, with the following 
contents:

> # Cherrypick the firmware files that we need for our hardware
>
> #FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
>
> PACKAGES += "${PN}-rtl8168d-1"
>
> FILES_${PN}-rtl8168d-1 = " \
>   /lib/firmware/rtl_nic/rtl8168d-1.fw \
> "


However, running "bitbake linux-firmware" fails with this bbappend file 
present:


> ERROR: No recipes available for:
> /home/markus/yocto/genericx86-64-dora-10.0.0/meta-markus/recipes-kernel/linux-firmware/linux-firmware.bbappend
> ERROR: Command execution failed: Exited with 1


Other bbappend files, such as for custom kernel config for linux-yocto, 
worked without complaints.

So far, I was following the instructions for using bbappend files here:
http://www.yoctoproject.org/docs/1.5/dev-manual/dev-manual.html#using-bbappend-files
http://www.yoctoproject.org/docs/current/kernel-dev/kernel-dev.html


 From what I can see, I am setting up my linux-firmware.bbappend file 
consistently with the instructions.

What am I doing wrong here?

Thanks very much
Markus