VTK 5.6.1 fails to build against Tcl 8.6.1.1 due to errorline being declared private in the Tcl_Interp structure
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
The problem is that by default, the members of the Tcl_Interp structure are no longer visible by default in the public header.
As a result errorLine is not accessible, and should instead be accessed using Tcl_GetErrorLine
This issue appears to have already been raised on the developer list:
http://www.vtk.org/pipermail/vtk-developers/2010-June/007993.html
But no bug appears to have been filed and checking the latest source from git, VTK/Common/vtkTclUtil.cxx still uses the errorLine rather then Tcl_GetErrorLine.