Ned Konz <ned at bike-nomad.com> gave possibly the most helpful answer yet.

Is 3.0pre2 the best available VM for Squeak 2.8?  I know perfectly well
what to do with a 'configure' file, and the variously named INSTALL file
is sufficiently clear anyway.  What it *doesn't* say, and what I *don't*
know is whether that version of the VM does actually work with the
"Squeak 2.8 final" changes and image file.

	So you should be able to just go:
	
		mkdir $HOME/squeak
		cd build
		../src/unix/configure --prefix=$HOME/squeak
		make
		make install
	
	Now, I haven't tried this, but it seems like it should work.
	
Is there anyone else who _has_ tried it?
I have 2.8pre4 building right now; I just hope the slight touch of clock skew
make: *** Warning: File `Makefile' has modification time in the future
doesn't affect things.  (No, I can't reset the clock.  You have to be root
to do that.  See previous messages in this thread.)