This is, unfortunately, necessary, and will remain so until all of the
   backdoor arguments passed through the environment move to command-line
   options.  (The ones I'm most aware of, because they're the ones I've
   used recently, are TOOLDIR, NOCLEANDIR, and USETOOLS, but there are
   many more; /usr/src/BUILDING includes a fairly long list.)


note that a lot of these can be passed as arguments to build.sh.


.mrg.