When launching VNL after installing it, you may experience the following kind of error message:
QT ('Not available', '/home/user/vnl-2008.10.0/lib/python2.4/site-packages/qtext.so: cannot restore segment prot after reloc: Permission denied')
This can also occur for ATK, in which case the error message will point to the file lib/python2.4/_PyATK.so.
The cause of this error are the new kernel security extensions from the SELinux project which are enabled in some newer Linux distributions, to allow finer-grained control over system security and shared library loading. The solution is to register the relevant libraries in the security module to allow them to be relocated in memory.
For VNL:
chcon -t texrel_shlib_t lib/python2.4/site-packages/qtext.so
For ATK:
chcon -t texrel_shlib_t lib/python2.4/_PyATK.so
Don't forget that there is a local ATK installation inside the VNL installation too, which needs to be registered separately.