Turns out is is an issue originated from linux-backports: https://git.kernel.org/pub/scm/linux/kernel/git/backports/backports.git/tree/backport/Makefile
Turns out is is an issue originated from linux-backports: https:/ /git.kernel. org/pub/ scm/linux/ kernel/ git/backports/ backports. git/tree/ backport/ Makefile