On Mon, Jan 29, 2018 at 10:32:47 -0500, Sean McBride wrote: > Most/all(?) of them use the system zlib though, perhaps you broke > something related to that? That would be it. vtkpng is linking to it as a target, but it isn't a target in the use-system case. Instead, `vtkzlib_LIBRARIES` would need to be used. --Ben