I have a minor problem with mkmf (ruby 1.6.7) and gmake.

mkmf generates implicite dependencies for ".cxx" files,
such as:


all:		example.o
..cxx.o :
	g++ -c $@ $<


(I have reduced the example to minimum)

The problem is that it does NOT work with gmake,
it says:

No rule to make target `example.o', needed by `all'.  Stop.

Remark: if you substitute "cxx" by "C", then it works.

I have two questions:

1) Why does the mkmf generates dependencies which do not work?
    (It took at least 15 minutes to find out the problem,
     since the Makefile looked "right". It is really nasty.

2) Why does not it generates dependencies which work?

Best regards, Christian