First, I think the documentation has a bug: meta-mender/meta-mender-core/recipes-mender doesn’t contain a mender directory (nor mender_%.bb), so shouldn’t my layer contain recipes-mender/mender-client/mender-client_%.bbappend instead?
With this change, I did a bitbake -e mender-client and see this:
# $SYSTEMD_AUTO_ENABLE [4 operations]
# set /yocto-src/sources/poky/meta/conf/documentation.conf:403
# [doc] "For recipes that inherit the systemd class, this variable specifies whether the service you have specified in SYSTEMD_SERVICE should be started automatically or not."
# set? /yocto-src/sources/meta-mender/meta-mender-core/recipes-mender/mender-client/mender-client.inc:17
# "enable"
# set /yocto-src/sources/poky/meta/classes/systemd.bbclass:9
# [_defaultval] "enable"
# set /yocto-dev/layers/meta-orro/recipes-mender/mender-client/mender-client_%.bbappend:1
# "disable"
# pre-expansion value:
# "disable"
SYSTEMD_AUTO_ENABLE="disable"
#
but at runtime, you can see that it’s the right build (built a few minutes ago) but mender still daemonized:
root@hermes:~# uname -a
Linux hermes 5.4.24-2.1.0+gbabac008e5cf #1 SMP PREEMPT Thu May 27 15:34:35 UTC 2021 armv7l armv7l armv7l GNU/Linux
root@hermes:~# ps |grep mender
412 root 873m S /usr/bin/mender daemon
413 root 852m S /usr/bin/mender-connect daemon
2667 root 2248 S grep mender