It's been the case for some time that, e.g., doing a `make' in
x11/gnome on a fresh system seems to spin for a great deal of time
before it starts actually building dependencies.  I decided I was
tired of this problem and took a look at it.

The issue is that it recursively runs check-depends for all
uninstalled packages.  Unfortunately, it recurses into some rather
large subtrees (e.g. under gnome-libs) many times.  This can get very
expensive.

But the interesting thing is that this recursive process DOES NOTHING.
It doesn't output anything (c.f. ECHO_MSG=${TRUE:Q}); it doesn't build
or install anything (c.f. DEPENDS_TARGET=check-depends); it literally
accomplishes nothing at all -- save, perhaps, verifying that some
Makefiles exist.

And this lossage is activated by a harmless looking dependency:

real-fetch: check-depends

Commenting out this line makes the problem go away.  It still builds
and installs dependencies just like I'd expect; it just avoids the
useless and very slow tree walk.

Could someone please explain what `check-depends' is for?