Re: dependencies in other folders

[Martin d Anjou]

> make: Circular foo.c <- foo.c dependency dropped.
> make: `../b/foo.c' is up to date.
>
> Is it possible to solve it using VPATH?

I don't think so. VPATH is to find prerequisites, not targets.

The pattern matched by % is the same on both sides of the ":". And since 
foo.c: foo.c is the same file, it is circular. In your case, you can fix 
it with:

VPATH=../b
../a/%.c: %.c
        cp $< $@

Then from test_make/a you type:
make ../a/foo.c

The the path/filename cannot be the same for targets and their 
prerequisites otherwise it is circular.

Martin