as stated here http://proguard.sourceforge.net/GPL.html and here http://proguard.sourceforge.net/GPL_exception.html proguard is distributed under a GPL v2 (and later) version
No such thing in portage.
i don't understand. here is the ebuild http://packages.gentoo.org/search/?sstring=proguard # Copyright 1999-2006 Gentoo Foundation # Distributed under the terms of the GNU General Public License v2 # $Header: /var/cvsroot/gentoo-x86/dev-java/proguard/proguard-3.6.ebuild,v 1.1 2006/07/07 09:07:44 nelchael Exp $ inherit java-pkg-2 java-ant-2 DESCRIPTION="Free Java class file shrinker, optimizer, and obfuscator." HOMEPAGE="http://proguard.sourceforge.net/" SRC_URI="mirror://sourceforge/proguard/${PN}${PV}.tar.gz" LICENSE="GPL-1" SLOT="0" KEYWORDS="~x86" IUSE="doc examples" [...]
Hmmm, arrived into CVS now... It's not GPL-2, looks like GPL-2 with linking exception (http://proguard.sourceforge.net/GPL_exception.html)
Fixed, thanks.