looking at gnu/hello/Makefile we see:
include ../../gar.lib/info.mk
include ../../gar.lib/auto.mk
include config.mk
looking at ../../gar.lib/info.mk
we see that the first target is:
post-install:
printf "[$(OK)install-info$(OFF)] $(MSG)Installing entries to the Info
directory$(OFF)\n"
.............
so the default target is the first target, which installs the ".info" files.
Probably what was meant was to put ../../gar.lib/auto.mk BEFORE
../../gar.lib/info.mk
I've noticed this behaviour on other packages as well.