problem with double colon rules

[Maciej Walezak]

Hello,

My makefile looks as follows:

aa::
        touch $@
../bb::
        touch $@

Now I invoke the followin sequence

$ gmake aa
touch aa

$ gmake aa
gmake: `aa' is up to date.

$ gmake ../bb
touch ../bb

$ gmake ../bb
touch ../bb

As you can see, the rule for ../bb is always execute regardless if ../bb exist 
or not.

Here is an excerpt from debug log for 'aa':
Considering target file `aa'.
 Finished prerequisites of target file `aa'.
No need to remake target `aa'.

And here is an excerpt from debug log for '../bb':
Considering target file `../bb'.
 Finished prerequisites of target file `../bb'.
Target `../bb' is double-colon and has no prerequisites.
Must remake target `../bb'.

Can anybody explain to me this behaviour?

--
Maciej Walezak
-GDN-