Upstream author has uploaded his working tree to github, which can be
accessed at : https://github.com/semsol/arc2

To download versions of upstream's sources, one may check the
get-orig-source rule and use : 
 $ debian/rules get-orig-source

FYI, the Debian package is maintained in git at
http://anonscm.debian.org/gitweb/?p=pkg-php/php-arc.git;a=summary
(integrating the merged upstream git repo), using git-buildpackage,
and may be regenerated with a command-line like :
 $ git-buildpackage

 -- Olivier Berger <obergix@debian.org>, Thu,  9 May 2013 16:44:17 +0200
