WARNING: nanomind-dev-image-1.0-r0 do_rootfs: nanomind-gpio-ctrl.postinst returned 1, marking as unpacked only, configuration required on target.
WARNING: nanomind-dev-image-1.0-r0 do_rootfs: nanomind-bank-ctrl.postinst returned 1, marking as unpacked only, configuration required on target.
ERROR: nanomind-dev-image-1.0-r0 do_rootfs: Postinstall scriptlets of ['nanomind-gpio-ctrl', 'nanomind-bank-ctrl'] have failed. If the intention is to defer them to first boot,
then please place them into pkg_postinst_ontarget:${PN} ().
Deferring to first boot via 'exit 1' is no longer supported.

I noticed this particular commit, and reverting it resolves the breakage. The recipe is quite trivial IMO:

inherit systemd

RDEPENDS:${PN} = "libgpiod-tools"

SYSTEMD_SERVICE:${BPN} = "${BPN}@.service"

SRC_URI = "file://${SYSTEMD_SERVICE:${BPN}}"

S = "${WORKDIR}/sources"
UNPACKDIR = "${S}"

do_install () {
install -d ${D}${systemd_system_unitdir}
install -m 0644 ${UNPACKDIR}/${SYSTEMD_SERVICE:${BPN}} ${D}${systemd_system_unitdir}
}