Version 2.18.13 of sci-geosciences/qgis is available: https://github.com/qgis/QGIS/commit/8cba0bb9eb005d354094d0e8372e10bdb22205d4
This will be the last 2.18.x version bump I'll be looking into.
Done in git commit e37d84b520ce9c806cb4a38cccddd866fe4b1435