Fixing DocNav 2017.04 on Debian Stretch

Having installed Vivado 2017.04 on one of my GNU/Linux machines that run Debian 9.3 (Stretch), I realized that DocNav fails to start:

dzu@deepthought:~$ . /opt/Xilinx/Vivado/2017.4/settings64.sh
dzu@deepthought:~$ docnav
docnav: error while loading shared libraries: libpng12.so.0: cannot open shared object file: No such file or directory
dzu@deepthought:~$

It turns out that Stretch currently does not carry libpng in version 12 and that the corresponding package from Jessie cannot be installed correctly:

dzu@deepthought:~$ sudo dpkg --install ~/Downloads/libpng12-0_1.2.50-2+deb8u3_amd64.deb
(Reading database ... 273874 files and directories currently installed.)
Preparing to unpack .../libpng12-0_1.2.50-2+deb8u3_amd64.deb ...
Unpacking libpng12-0:amd64 (1.2.50-2+deb8u3) ...
dpkg: error processing archive /home/dzu/Downloads/libpng12-0_1.2.50-2+deb8u3_amd64.deb (--install):
 unable to install new version of '/usr/lib/x86_64-linux-gnu/libpng12.so.0': No such file or directory
Errors were encountered while processing:
 /home/dzu/Downloads/libpng12-0_1.2.50-2+deb8u3_amd64.deb
dzu@deepthought:~$

For me the solution was to download libpng12-0 from Wheezy and install it. Now DocNav runs without any further problems.

One should keep in mind that this package has some known CVEs associated with it, but given that it will only be used by DocNav and this only shows data provided directly by Xilinx, the risk of doing so is qualified. DocNav should really move to a newer version of libpng to fix this completely.

Also note that DocNav was only recently ported to 64 bit, so some of the available information on the Xilinx website is no longer accurate, especially the DocNav part of Answer Record #66184.