Problem with a GNUmakefile for a framework with "special" headers

[Nat!]

Hi

me again, with another problem. This is when building a framework. I have some 
headers that are located outside of the main source tree.

The filesystem structure is like this:

        x/a.h
        y/z/b.m
        y/z/GNUmakefile

so in the GNUmakefile its like this:

        z_HEADER_FILES = ../../x/a.h

the GNUstep make system copies that file to

        z.framework/Versions/1.0.0/Headers/../../x/a.h

which ends up in the wrong place

        z.framework/Versions/x/a.h

I suspect that this target in 
/usr/share/GNUstep/Makefiles/Instance/framework.make is the culprit, but I 
don't have an idea how and if this can be fixed.

$(FRAMEWORK_VERSION_DIR)/Headers/%.h:   $(HEADER_FILES_DIR)/%.h
        $(ECHO_CREATING)$(INSTALL_DATA) $< address@hidden(END_ECHO)

I blindly tried, not knowing much gnu make, 

$(FRAMEWORK_VERSION_DIR)/Headers/$(<D): $(HEADER_FILES_DIR)/%.h
        $(ECHO_CREATING)$(INSTALL_DATA) $< address@hidden(END_ECHO)

but it didn't work.

Ciao
   Nat!

P.S. It be cool, if I could be spared the meta-discussion, on why I have it 
structured like this and specifically religious rants against those practices. 
:)
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Why should I have to work for everything ?! 
It's like saying I don't deserve it. -- Watterson