To build the package do the following:
sudo apt-get build-dep graphviz
sudo aptitude install bzr-builddeb
bzr branch lp:~simono/ubuntu/karmic/graphviz/fixes-bug-414057
cd fixes-bug-414057
bzr-buildpackage -e
cd ../build-area/graphviz-2.20.2
debuild -us -uc -b
tcl8.5 is the package which contains tclsh8.5.
To build the package do the following: area/graphviz- 2.20.2
sudo apt-get build-dep graphviz
sudo aptitude install bzr-builddeb
bzr branch lp:~simono/ubuntu/karmic/graphviz/fixes-bug-414057
cd fixes-bug-414057
bzr-buildpackage -e
cd ../build-
debuild -us -uc -b