Thanks to Hans suggestions I made a research why I cant compile pd-ex from branch. It takes me some time but I found that was something wrong in GEM configure.ac script. So I did it !
https://aur.archlinux.org/packages.php?ID=44798
---> should be the correct build package script for the latest pd-extended It is made from:
https://pure-data.svn.sourceforge.net/svnroot/pure-data/branches/pd-extended...
git://pure-data.git.sourceforge.net/gitroot/pure-data/pd-extended.git
{I apologize all the guys who liked pd-extended with the latest GEM, but (I understand this) it is 'official' package of pd-ex, now.}
fero