Bug#1125167: SPAM: Bug#1125167: vtk9: libucs crashes the JVM

[Drew Parsons]

On 2026-02-23 15:54, Jean-Max Redonnet wrote:
> Hi Drew!
> 
> For the moment I do not have enough space on my disk to install a 
> virtual machine running forky. Sorry.
> 
> Getting an example reproducing the problem is quite easy: Once vtk9 and 
> libvtk9-java are properly installed with dependencies, just grab any 
> java example from https://examples.vtk.org/site/Java/

Thanks Jean-Max. https://examples.vtk.org/site/Java/ is helpful.

Kitware seems to be treating java support as deprecated.
The doc link http://www.vtk.org/Wiki/VTK/Tutorials/JavaEnvironmentSetup
for setting up java for VTK is broken.

> Compile it, run it and admire the crash... At least if your computer 
> acts exactly as mine.

Yeah, compiling it is quite the issue, before even thinking about 
libucs.  There are bigger problems here than libvtk9-java. java doesn't 
even know where it's own libraries (libjawt.so) are,

java.lang.UnsatisfiedLinkError: 
/usr/lib/x86_64-linux-gnu/java/vtk-Linux-x86_64/libvtkRenderingCoreJava.so: 
libjawt.so: cannot open shared object file: No such file or directory

which doesn't bode well for getting libvtk9-java to operate painlessly.

But with some stubborness, your CylinderExample.java can be made to 
display a red cylinder, fully rotatable.

$ 
LD_LIBRARY_PATH=/usr/lib/jvm/java-21-openjdk-amd64/lib/:/usr/lib/x86_64-linux-gnu/java/vtk-Linux-x86_64/ 
java -cp "/usr/share/java/vtk9.jar"  CylinderExample.java
java.lang.UnsatisfiedLinkError: 
/usr/lib/x86_64-linux-gnu/java/vtk-Linux-x86_64/libvtkRenderingMatplotlibJava.so: 
/usr/lib/x86_64-linux-gnu/java/vtk-Linux-x86_64/../../libvtkWrappingPythonCore3.13-9.5.so.1: 
undefined symbol: PyExc_ValueError
	at java.base/jdk.internal.loader.NativeLibraries.load(Native Method)
	at 
java.base/jdk.internal.loader.NativeLibraries$NativeLibraryImpl.open(NativeLibraries.java:331)
	at 
java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:197)
	at 
java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:139)
	at 
java.base/jdk.internal.loader.NativeLibraries.findFromPaths(NativeLibraries.java:259)
	at 
java.base/jdk.internal.loader.NativeLibraries.loadLibrary(NativeLibraries.java:251)
	at java.base/java.lang.ClassLoader.loadLibrary(ClassLoader.java:2451)
	at java.base/java.lang.Runtime.loadLibrary0(Runtime.java:916)
	at java.base/java.lang.System.loadLibrary(System.java:2063)
	at vtk.vtkNativeLibrary.LoadLibrary(vtkNativeLibrary.java:255)
	at 
vtk.vtkNativeLibrary.LoadAllNativeLibraries(vtkNativeLibrary.java:192)
	at CylinderExample.<clinit>(CylinderExample.java:17)
	at java.base/java.lang.Class.forName0(Native Method)
	at java.base/java.lang.Class.forName(Class.java:536)
	at java.base/java.lang.Class.forName(Class.java:515)
	at 
jdk.compiler/com.sun.tools.javac.launcher.Main.execute(Main.java:432)
	at jdk.compiler/com.sun.tools.javac.launcher.Main.run(Main.java:208)
	at jdk.compiler/com.sun.tools.javac.launcher.Main.main(Main.java:135)
vtkRenderingMatplotlibJava not loaded

I'm not sure what to make of the undefined PyExc_ValueError. Looks like 
libvtkWrappingPythonCore3.13-9.5.so.1 needs to link to libpython3.13.so. 
But it's not preventing your cylinder from displaying.

Looks like the libucs crash has been resolved.