Re: No rule to make target `../../build-aux/snippet/arg-nonnull.h'

[martin rudalics <rudalics@gmx.at>]

 > Weird. Master contains no references to
 > build-aux/snippet/arg-nonnull.h other than in
 > msdos/autogen/Makefile.in (which I assume you are not using). So there
 > must be something old lying in your directory. Does it fix things to
 > remove nt/gnulib.mk and then rebuild?

Yes.  The build succeeded.

 > If not, what does this output?
 > grep -FRl build-aux/snippet/arg-nonnull.h .

I had two (didn't check now).  One in /nt/gnulib.mk

BUILT_SOURCES += arg-nonnull.h
# The arg-nonnull.h that gets inserted into generated .h files is the same as
# build-aux/snippet/arg-nonnull.h, except that it has the copyright header cut
# off.
arg-nonnull.h: $(top_srcdir)/build-aux/snippet/arg-nonnull.h
	$(AM_V_GEN)rm -f $@-t $@ && \
	sed -n -e '/GL_ARG_NONNULL/,$$p' \
	  < $(top_srcdir)/build-aux/snippet/arg-nonnull.h \
	  > $@-t && \
	mv $@-t $@

@BUILDING_FOR_WINDOWSNT_TRUE@	$(top_srcdir)/build-aux/snippet/arg-nonnull.h \

and one in /lib/Makefile.in

# The arg-nonnull.h that gets inserted into generated .h files is the same as
# build-aux/snippet/arg-nonnull.h, except that it has the copyright header cut
# off.
@BUILDING_FOR_WINDOWSNT_TRUE@arg-nonnull.h: $(top_srcdir)/build-aux/snippet/arg-nonnull.h
@BUILDING_FOR_WINDOWSNT_TRUE@	$(AM_V_GEN)rm -f $@-t $@ && \
@BUILDING_FOR_WINDOWSNT_TRUE@	sed -n -e '/GL_ARG_NONNULL/,$$p' \
@BUILDING_FOR_WINDOWSNT_TRUE@	  < $(top_srcdir)/build-aux/snippet/arg-nonnull.h \
@BUILDING_FOR_WINDOWSNT_TRUE@	  > $@-t && \
@BUILDING_FOR_WINDOWSNT_TRUE@	mv $@-t $@

Thanks for helping, martin