Google .. vpath .. http://www.google.com/webhp
The first hit says : How Not to Use VPATH
QUOTE : "..rather than the current directory, is by prefixing all the
targets with that directory path. In other words, VPATH is useless
to us for this purpose.
QUOTE.. (with line numbers from 'grep -n vpath make_4.txt'
163: directory `src'. The |vpath| Directive Similar to the |VPATH| variable
164: but more selective is the |vpath| directive (note lower case), which
169: the |vpath| directive: |vpath pattern directories| Specify the search
173: variable. |vpath pattern| Clear out the search path associated with
174: pattern. |vpath| Clear all search paths previously specified with
175: |vpath| directives. A |vpath| pattern is a string containing a `%'
181: exactly, which is not useful very often.) `%' characters in a |vpath|
188: if the pattern in a |vpath| directive matches the name of the
191: example, vpath %.h ../headers tells |make| to look for any dependency
193: not found in the current directory. If several |vpath| patterns match
194: the dependency file's name, then |make| processes each matching |vpath|
196: directive. |make| handles multiple |vpath| directives in the order in
198: pattern are independent of each other. Thus, vpath %.c foo vpath %
199: blish vpath %.c bar will look for a file ending in `.c' in `foo', then
200: `blish', then `bar', while vpath %.c foo:bar vpath % blish will look
219: specified in |VPATH| or with |vpath| also happens during consideration
237: specified by matching |vpath| search paths and the |VPATH| search path,
Parallel Build Trees (a.k.a. VPATH Builds)
.. And then also ... another 733,000 hits .. ..