(http://phd-sid.ethz.ch/debian/opentoonz)
From https://github.com/opentoonz/opentoonz/blob/master/doc/how_to_build_linux.md:
Building LibTIFFTODO: make sure we can use the system libtiff instead and remove this section. Features from the modified libtiff are needed currently, so this isn't a simple switch.
Best,