kmk: $(commands ) and $< doesn't work quite well together.

[bird]

This doesn't work (from src/VBox/HostDrivers/Support/Makefile.kmk):

$(PATH_BIN)/src/Makefile: \
		$(PATH_SUB_CURRENT)/linux/Makefile \
		$$(warning 1=$$(commands $$(PATH_BIN)/src/Makefile)) \
		$$(warning 2=$$(Support/linux/Makefile_CMDS_PREV)) \
		$$(comp-cmds-ex $$(Support/linux/Makefile_CMDS_PREV),$$(commands $$(PATH_BIN)/src/Makefile),FORCE)
	$(call MSG_TOOL,Creating,,$@)
ifndef VBOX_WITH_HARDENING
	$(QUIET)$(SED) -e "s;-DVBOX_WITH_HARDENING;;g" --output $@ $<
else
	$(QUIET)$(CP) -f $< $@
endif
	%$(QUIET2)$(RM) -f -- $(PATH_TARGET)/vboxmod-1.dep
	%$(QUIET2)$(APPEND) '$(PATH_TARGET)/vboxmod-1.dep' 'define Support/linux/Makefile_CMDS_PREV'
	%$(QUIET2)$(APPEND) -c '$(PATH_TARGET)/vboxmod-1.dep' '$@'
	%$(QUIET2)$(APPEND) '$(PATH_TARGET)/vboxmod-1.dep' 'endef'

-include $(PATH_TARGET)/vboxmod-1.dep

[bird]

This isn't easily fixed, so noting it down as a restriction and adding an error (non-fatal) for when it's encountered ([1698]). It may be possible to get the $< working, but it's not gonna be pretty or fun...