--- a/chemical-mime-data-0.1.94-r3.ebuild	2019-07-29 14:13:38.579079151 +0200
+++ b/chemical-mime-data-0.1.94-r4.ebuild	2019-07-29 14:09:13.204677821 +0200
@@ -12,7 +12,12 @@
 LICENSE="LGPL-2.1"
 SLOT="0"
 KEYWORDS="amd64 arm arm64 x86"
-IUSE=""
+IUSE="opencl"
+
+# With opencl, write acces to /dev/dri/card0 is needed and the portage
+# user is (usually) not in the video group
+# See #578628 and references therein.
+RESTRICT="userpriv"
 
 RDEPEND="
 	gnome-base/gnome-mime-data
@@ -41,6 +46,11 @@
 }
 
 src_configure() {
+	if use opencl; then
+		addwrite /dev/dri/card0
+		addwrite /proc/mtrr
+	fi
+
 	local myeconfargs=(
 		--disable-update-database
 		--htmldir=/usr/share/doc/${PF}/html