Mailing List Archive: Python / VTK problem

Hi, folks. I've just downloaded, compiled, and installed VTK 2.3, and
for the first time, I've
built with Python extensions enabled. Unfortunately, while I can run
the Tcl examples, I
can't get the Python examples to run. The command 'python mace.py' (or
similar) produces:

Traceback (innermost last):
File "./mace.py", line 2, in ?
from libVTKGraphicsPython import *
ImportError: /home/gvwilson/lib/libVTKGraphicsPython.so: undefined
symbol: XtStrings

The symbols XtStrings is defined in /usr/X11R6/lib/libXt.so (I'm on Red
Hat Linux). The directory
/usr/X11R6/lib is in my LD_LIBRARY_PATH and in my PYTHONPATH, as is
/home/gvwilson/lib
(which contains symbolic links to the VTK .so's). I'd be grateful to
anyone who can tell me what I'm
doing wrong.
Thanks,
Greg
(p.s. I'd also be grateful if you'd reply by direct email to g v w i l s
o n @ n e v e x . c o m)

Greg Wilson:
|Hi, folks. I've just downloaded, compiled, and installed VTK 2.3, and
|for the first time, I've built with Python extensions enabled.
|Unfortunately, while I can run the Tcl examples, I can't get the Python
|examples to run. The command 'python mace.py' (or similar) produces:
|
| Traceback (innermost last):
| File "./mace.py", line 2, in ?
| from libVTKGraphicsPython import *
|ImportError: /home/gvwilson/lib/libVTKGraphicsPython.so: undefined
|symbol: XtStrings
|
|The symbols XtStrings is defined in /usr/X11R6/lib/libXt.so (I'm on Red
|Hat Linux). The directory /usr/X11R6/lib is in my LD_LIBRARY_PATH and in
|my PYTHONPATH, as is /home/gvwilson/lib (which contains symbolic links to
|the VTK .so's). I'd be grateful to anyone who can tell me what I'm doing
|wrong.

It sounds like libVTKGraphicsPython.so wasn't implicitly linked with
libXt.so when you compiled VTK. No problems here on IRIX; it appears that
the linker pulled it in automatically.

To check:

> cd vtk/graphics
> ldd libVTKGraphicsPython.so
[.you should see libXt.so in the list; but I'd wager that you won't]
> rm libVTKGraphicsPython.so
> make
[VTK doesn't explicitly link in Xt, but it probably should]

A quick nm of the source files linked into libVTKGraphicsPython reveals
that vtkXRenderWindowInteractor.o depends on Xt calls.

Try adding a:

X_EXTRA_LIBS = -lXt -rpath /usr/X11R6/lib

to your user.make file.

Randall