multi-architecture builds and recursive makes

[Robert P. J. Day]

  i'm reading paul smith's essay on multi-architecture builds
(http://make.paulandlesley.org/multi-arch.html), but it seems that that 
approach wouldn't work if one had a recursive make structure, would it?

  that is, say one had the source directory SRCDIR and the directory in
which to build the objects OBJDIR, the *general* form of the make
invocation would be (simplified drastically for brevity):

  $ cd ${SRCDIR}
  $ make -C ${OBJDIR} -f ${SRCDIR}/Makefile <target>

that would work fine for simple targets, but if the Makefile had a
recursive structure that tried to "make" into SRCDIR's subdirectories, it
seems this would fail as the make (running effectively in OBJDIR) would
try to locate the subdirectories in OBJDIR, not SRCDIR, would fail to find
them, and abort, no?  (a quick test seems to verify this behaviour.)

  i have a couple followup questions about multi-arch builds, but i'll 
hold off until i clarify this point.  thanks.

rday