vtkLocalExample.java randomly missing from vtk.jar

While working on reproducible builds for openSUSE, I found that building openSUSE's vtk package resulted in a vtk.jar that only contained the vtkLocalExample.java and vtkLocalExample.class files if the build happened in parallel, but not with -j1

Build logs (with grep -e vtk.jar -e vtkLocalExample.java) make it pretty clear that there is some dependency missing in CMakeLists:

-j4
vtk/RPMS.2/.build.log:[  464s] [  9%] Java Wrappings - generating vtkLocalExample.java
vtk/RPMS.2/.build.log:[  464s] cd /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/Examples/Build/vtkLocal && ../../../bin/vtkParseJava @/home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/Examples/Build/vtkLocal/vtkLocalExampleJava.RelWithDebInfo.args -o /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/java/vtk/vtkLocalExample.java /home/abuild/rpmbuild/BUILD/VTK-8.2.0/Examples/Build/vtkLocal/vtkLocalExample.h
vtk/RPMS.2/.build.log:[ 3533s] cd /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/Wrapping/Java && /usr/lib64/jvm/java/bin/jar -cvf /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/lib/vtk.jar -C /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/java vtk
vtk/RPMS.2/.build.log:[ 3535s] adding: vtk/vtkLocalExample.java(in = 461) (out= 214)(deflated 53%)
vtk/RPMS.2/.build.log:[ 4698s] -- Installing: /home/abuild/rpmbuild/BUILDROOT/vtk-openmpi2-8.2.0-0.0.x86_64/usr/lib64/mpi/gcc/openmpi2/lib64/vtk.jar

-j1
vtk/RPMS/.build.log:[ 7926s] cd /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/Wrapping/Java && /usr/lib64/jvm/java/bin/jar -cvf /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/lib/vtk.jar -C /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/java vtk
vtk/RPMS/.build.log:[12577s] [100%] Java Wrappings - generating vtkLocalExample.java
vtk/RPMS/.build.log:[12577s] cd /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/Examples/Build/vtkLocal && ../../../bin/vtkParseJava @/home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/Examples/Build/vtkLocal/vtkLocalExampleJava.RelWithDebInfo.args -o /home/abuild/rpmbuild/BUILD/VTK-8.2.0/build/java/vtk/vtkLocalExample.java /home/abuild/rpmbuild/BUILD/VTK-8.2.0/Examples/Build/vtkLocal/vtkLocalExample.h
vtk/RPMS/.build.log:[14008s] -- Installing: /home/abuild/rpmbuild/BUILDROOT/vtk-openmpi2-8.2.0-0.0.x86_64/usr/lib64/mpi/gcc/openmpi2/lib64/vtk.jar