=?utf-8?q?PG_Bug_reporting_form?= <noreply(at)postgresql(dot)org> writes:
> We build postgresql as part of a larger runtime environment, and if the
> top-level make is invoked from an existing, other Makefile (i.e., with
> $MAKELEVEL set), the build fails like this:
> ...
> Workaround for us was to use
> MAKELEVEL=0 $(MAKE)
> instead.
Yeah, this is now documented, near the bottom of the "2. Build" step at
https://www.postgresql.org/docs/11/static/install-procedure.html
It should be harmless to do that for pre-11 versions too.
regards, tom lane