[vtkusers] Problem with building VTK

[Ben Boeckel]

On Tue, Apr 18, 2017 at 10:15:16 +0200, Mathieu Westphal wrote:
> Your compiler is too recent for this version of vtk. You should either use
> the last version of vtk or install an older GCC ( can't give you the
> version right now )

IIRC, the regex fails for 6 and up. You can fix it locally, but I doubt
this is the end of the problems with VTK5 on newer machines:

    https://gitlab.kitware.com/vtk/vtk/commit/52501fd085a64b55d1b53d40c1d3f86c6ce9addd
    https://gitlab.kitware.com/vtk/vtk/commit/06e2a00bf8accb04db63b3c1c7a454e4afc6fea6
    https://gitlab.kitware.com/vtk/vtk/commit/77bd9900662770d83042f3ca8198d7908bba1d63

--Ben