The dependency port graphics.osg complains:
> Error: /usr/local/lib/osgPlugins-3.5.9/osgdb_iv.so is linked to /usr/local/lib/libInventor.so which does not have a SONAME. graphics/inventor needs to be fixed.
Port is marked BROKEN= unfetchable.
I think we can Deprecate this port.
graphics/osg and graphics/osg-devel depend on it through their INVENTOR option.
Also, there is a runtime-conflict of graphics/inventor with some other package though I can't find it now. One of them includes the other one.
Also Debian, Fedora, MacPorts have packages for inventor: https://repology.org/project/inventor/versions
I asked the Fedora's inventor port long-time maintainer firstname.lastname@example.org if he thinks that it should be deprecated.
DEPRECATED= Depends on expiring graphics/libGLw