I've just installed dev-libs/boost-1.35.0-r3 and dev-libs/boost-1.36.0. # eselect boost list Available boost versions: [1] boost-1_35 [2] boost-1_36 # eselect boost show Current boost version: (unset) # eselect boost update !!! Error: Couldn't remove existing installation Terminado (killed) Maybe boost should set a version when none is set yet, and 'update' should not fail when none is set.
It might also be worth it to call eselect after merging a boost version. i.e. after installing boost 1.37 (which is currently masked), portage will un-emerge the current version of boost (in my case 1.35), which left the /usr/include/boost symlink pointing nowhere.
Bug solved in version 0.2. No, portage will/should not automatically un-merge 1.35 since they're in different slots. That's the reason why we need boost-eselect after all.