Hi Paul,
POSIX documents MAKEFLAGS thusly:
Before the makefile(s) are read, all of the make utility command line
options (except -f and -p) and make utility command line macro
definitions (except any for the MAKEFLAGS macro), not already included
in the MAKEFLAGS macro, shall
I would agree that GNU make's behavior here is not according to the
standard... it looks like you're right: the flags that are in MAKEFLAGS
as a consequence of the initial invocation of make take precedence and
no extra flags that are added to a "sub-make" will be added to
MAKEFLAGS.
I tested back