Re: "No rule to make target" in a BUILT_SOURCES, non-recursive, multi-directory project

[Ralf Wildenhues]

Hi Jeff,

* Daily, Jeff A wrote on Tue, Aug 10, 2010 at 08:54:53PM CEST:
> I am using subdir-objects and I have a single, top-level Makefile.am:
> 
> #*snip*
> BUILT_SOURCES =
> lib_LTLIBRARIES = libfoo.la
> libfoo_la_SOURCES =
> #*snip*
> If HAVE_PYTHON
> BUILT_SOURCES += foo/bar/wapi.c
> foo/bar/wapi.c: foo/bar/papi.h $(top_srcdir)/build-aux/wapi.py
>         -rm -f foo/bar/wapi.c && \
>         $(PYTHON) $(top_srcdir)/build-aux/wapi.py $< > foo/bar/wapi.c
> libfoo_la_SOURCES += foo/bar/wapi.c
> endif
> #*snip*
> 
> It turns out that $(PYTHON) is located by configure such that
> HAVE_PYTHON is true.  When I configure and build from a subdirectory
> within my source tree e.g. "mkdir bld; cd bld; ../configure" the build
> fails because make is looking for the target "../foo/bar/wapi.c" which
> doesn't exist,

Which make version and implementation, which Automake version?
Do you somehow ensure foo/bar exists in the build tree beforehand?
Does the file foo/bar/papi.h exist in the source or in the build tree?

The above works for me; but VPATH target lookup is tricky across
make implementations, see 'info Autoconf "VPATH and Make"' and
the last node referenced therein.

Using $< in non-inference rules is not portable to non-GNU make.

Cheers,
Ralf