'emerge -uvDN --backtrack=30 @world' fails with: root@lynx:/root(21)# emerge -uvDN --backtrack=30 @world These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild U ] dev-python/numpy-1.9.2::gentoo [1.8.2::gentoo] USE="doc lapack {-test}" PYTHON_TARGETS="python2_7 python3_3 -python3_4" 0 KiB ... [ebuild U ] dev-python/bottleneck-1.0.0::gentoo [0.8.0::gentoo] PYTHON_TARGETS="python2_7 python3_3 -python3_4" 0 KiB ... [ebuild U ] sci-mathematics/sage-6.6::sage-on-gentoo [6.5::sage-on-gentoo] USE="latex testsuite -arb% -debug -modular_decomposition%" PYTHON_TARGETS="python2_7" 0 KiB [ebuild U ] sci-mathematics/sage-doc-6.6::sage-on-gentoo [6.5::sage-on-gentoo] USE="html" LINGUAS="de%* en%* fr%* ru%* -ca% -hu% -it% -pt% -tr%" PYTHON_TARGETS="python2_7" 0 KiB Total: 7 packages (5 upgrades, 1 new, 1 reinstall), Size of downloads: 0 KiB !!! Multiple package instances within a single package slot have been pulled !!! into the dependency graph, resulting in a slot conflict: dev-python/numpy:0 (dev-python/numpy-1.9.2:0/0::gentoo, ebuild scheduled for merge) pulled in by >=dev-python/numpy-1.9.1[python_targets_python2_7(-)?,python_targets_python3_3(-)?,python_targets_python3_4(-)?,-python_single_target_python2_7(-),-python_single_target_python3_3(-),-python_single_target_python3_4(-)] required by (dev-python/bottleneck-1.0.0:0/0::gentoo, ebuild scheduled for merge) ^^ ^^^^^ (dev-python/numpy-1.8.2:0/0::gentoo, installed) pulled in by =dev-python/numpy-1.8*[python_targets_python2_7(-)?,-python_single_target_python2_7(-)] required by (sci-mathematics/sage-6.6:0/0::sage-on-gentoo, ebuild scheduled for merge) ^ ^^^^ Bottleneck is a dependence of pandas-0.16.0, which is again a dependency of rpy.
Is it still an issue?