I'm confused... why is there a new patch on gerrit for the Tcl 8.6 patches? The existing Tcl 8.6 patch (see link below) is already based on VTK 5.10.1. It just has to be merged into the VTK 5.10 release branch: http://review.source.kitware.com/#/t/2360/ There must be something that I'm not understanding here... David