So using this logic you'd also download something like gcc and then start
   dropping your random source into
   
   gcc/*
   
   ? (it will break you if you setup a cross compiler in there then since it'll
   put as/ld links into that directory..)

this *exact* argument isn't valid.  the gcc tree starts at (in, eg, our
tree) "toolchain/" which is the *parent* of "gcc/*".  there is no such
lossage associated with adding subdirectories to `toolchain'... (except
where toolchain/{Makefile*,configure*} say otherwise..)

   
   or whatever other layout you want. But cross breeding them together isn't
   likely to always work well...



but it's what people have been doing ~forever.  never before has being
under `/usr/src' been a problem for any foreign sources... but now we're
trying to use too much magic.


perhaps have an explicit list of subdirectories that the tools will be
used for, not *everything* under src?  ie, the same list of SUBDIRS
from src/Makefile.



.mrg.