Dep sez: doc? ( ${PYTHON_DEPS} ) So you probably want; pkg_setup() { use doc && python-any-r1_pkg_setup } Otherwise, the package will bail out with USE=-python if there's no matching Python around.
Confirmed it is currently broken and it installs correctly applying the fix below. Thanks for that Michal.
Thanks! 17 Nov 2013; Pawel Hajdan jr -jsoncpp-0.5.0.ebuild, jsoncpp-0.5.0-r1.ebuild: Only setup python for USE=doc, bug #487574 by mgorny. Also tested by John W. Newman. Remove old.