Created attachment 517134 [details]
ebuild with workaround
The pcl_features-1.8.pc installed by the sci-libs/pcl-1.8.1 ebuild contains a bogus dependency on pcl_2d-1.8, a component that doesn't exist any more. The breakage obviously comes from upstream, but just removing the dependency is straightforward enough. So let's try and get this temp fix into portage, since doesn't seem to be doing a lot of maintenance releases.
*upstream [doesn't seem to be doing a lot of maintenance releases]