> When I did a "cvs checkout -P gnusrc" under /usr the GNU sources were
> installed to /usr/gnusrc.
>
> I already had some (not all GNU) source under src/gnu/dists which seems to
> be the same as gnusrc/dists (i.e. parts of gawk). I am unclear why I have
> two copies. (I believe that /usr/src/gnu/dist should be the same as
> /usr/gnusrc/gnu/dist; I don't think I should have two.)

src is a CVS alias that retrieves a merged NetBSD source tree in a format
appropriate for compiling and such, and when you check it out it puts all of
the sources under src.  The actually tree in CVS is split up into basesrc,
gnusrc, sharesrc and syssrc (which can be seen at cvsweb.netbsd.org).
Things can get confusing if you check out src and then later check out one
of the split versions.  If you just want the kernel stuff, though, syssrc
has the pieces you need.

If you take a look at the modules file in cvsweb
(http://cvsweb.netbsd.org/bsdweb.cgi/CVSROOT/modules) you can see how the
src alias is built from basesrc, gnusrc and so on.

Most of the documentation assumes that you have all of your sources under a
src tree, which you would have if you checked out the src module instead of
the sub-modules it's built from.

Hope this helps!  Mike.