Where to put non-GNU build system components

VMS doesn't have a complete GNU environment yet.  (See gnv.sf.net for
the status of this work.)  Thus, I have some files that would ordinarily
be build products from running ./configure and make that need to be part
of the VMS port.  Now, it seems the cleanest thing to do would be to
locate these all in ruby/vms, but I'm not sure exactly how.

I have one .opt file (linker options) and one .mms file (VMS's own
non-GNU makefile) per directory.  One idea I am considering would be to
put an entire skeletal build tree in CVS under ruby/vms/build and just
deposit the .opt and .mms files here.  The top-level descrip.mms file in
ruby/vms/build would then copy all source files into the build tree for
the build, and clean them up again afterwards, along with all other
build products.

Using this plan, we would have in CVS:

ruby/vms/build
ruby/vms/build/descrip.mms (top-level Makefile)
...
ruby/vms/build/ext/socket/descrip.mms
ruby/vms/build/ext/socket/link.opt
...

I am wary, though, of creating such a large directory structure in CVS,
given that deletion of CVS directories is impossible, and ultimately we
would like this "scaffolding" for a proper GNU tools based build system
to disappear.

Alternatively, I could include a single patchfile in CVS:

ruby/vms/build.diff

This patchfile could be used to create the build structure.  However,
maintaining this patchfile would be unpleasant.

Another alternative is that the .mms and .opt files could be generated
somehow.  But at this stage in the port, I don't know if I could write
such a generator, except for the very simple .opt files, without extra
data files per directory to support all of the specific needs of each
module.

Finally, if I felt that GNV would very soon provide a complete build
system so I could do away with these extra files, I could simply
maintain all of these files outside of CVS, with a view to replacing
them with a proper GNU-based build system as soon as GNV is ready.
However, I don't have faith that GNV will finish this work soon, and
besides it would make it difficult for any others to obtain the VMS port
and try to build it themselves.  This is my least favourite alternative,
but is in fact what I am doing today.

Thoughts, anyone?

Ben