'emerge -uvDNe --keep-going --backtrack=600 --verbose-conflicts system' fails with: ... [ebuild R ] dev-lang/yasm-1.3.0::gentoo USE="nls python" PYTHON_TARGETS="python2_7" 0 KiB [ebuild R ] dev-python/docutils-0.12::gentoo PYTHON_TARGETS="python2_7 python3_4 -pypy -pypy3 -python3_3 -python3_5" 0 KiB Total: 815 packages (3 upgrades, 812 reinstalls), Size of downloads: 9,374 KiB !!! Multiple package instances within a single package slot have been pulled !!! into the dependency graph, resulting in a slot conflict: dev-lang/ocaml:0 (dev-lang/ocaml-4.02.3:0/4.02.3::gentoo, ebuild scheduled for merge) pulled in by (no parents that aren't satisfied by other packages in this slot) (dev-lang/ocaml-4.02.1:0/4.02.1::gentoo, installed) pulled in by >=dev-lang/ocaml-3.10.2:0/4.02.1=[ocamlopt] required by (dev-ml/lablgl-1.05:0/1.05::gentoo, installed) ^^^^^^^^^^ >=dev-lang/ocaml-3.10.2:0/4.02.1=[ocamlopt] required by (dev-ml/camlidl-1.05-r1:0/1.05::gentoo, installed) ^^^^^^^^^^ >=dev-lang/ocaml-3.10:0/4.02.1=[ocamlopt] required by (dev-ml/lablgtk-2.18.3:2/2.18.3::gentoo, installed) ^^^^^^^^^^ >=dev-lang/ocaml-4.02:0/4.02.1=[ocamlopt] required by (dev-ml/camlp4-4.02.1_p3:0/4.02.1_p3::gentoo, installed)
After masking =dev-lang/ocaml-4.02.3 'emerge -uvDNe --keep-going --backtrack=600 --verbose-conflicts system' starts at least.
