The permission bug is occured at the first time import the libtiff module. It need libtiff4-dev package to generate the tiff_h_4_0_1.py at the path /usr/lib/python2.7/dist-packages/libtiff/ which need root permission.
So I added the depends of libtiff4-dev as Depends: of the binary package, and added a postinstall script to import it once to generate tiff_h_4_0_1.py when running as root.
pylibtiff_fixed_663490.patch
Description: Binary data
