Having stepped into the usual snare of GTK dependencies, I thought I'd
experiment with mksandbox.  I'm having a little trouble with X:

/usr/X11R6 on /usr/sandbox/usr/X11R6 type null (local, read-only)

and Packages.txt's advice to "make sure you install X".  

The package I'm trying to build is editors/manedit, a GTK package that
obviously needs X.  The GTK+ package tries to install itself to /usr/X11R6
and fails of course, preventing the build.  

What's the proper course here?  Do I undo the null mount, get the
distribution sets for X, and untar them while in /usr/sandbox?  

I don't have an X server on this machine; I would think I need only the X
client set.  

Thanks, 

--jkl