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.
chcon -t texrel_shlib_t lib/python2.4/site-packages/qtext.so
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.