Given that building into DESTDIR is the normal way of doing things,
should the 'dependall' and 'install' passes not simply be combined, such
that everything is installed right after it builds? This saves an entire
pass through the source tree, just like combining 'depend' and 'all'
did.

As it is, 'install' depends on 'dependall' anyway, which you can see
when you build with -k, so not only incurs the 'install' phase a whole
pass through the tree, it also re-does all the dependency analysis of
the earlier phases. So probably changing 'dependall' into 'install' in a
few places will do (most of) the trick.

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert      -- You author it, and I'll reader it.
\X/ rhialto/at/xs4all.nl        -- Cetero censeo "authored" delendum esse.