GraphVizPlugin breaks all wiki macros in Trac 11.3

[anonymous]

Well this seems simple enough to reproduce. When I enable GraphVizPlugin on 11.3 all my other wiki macros break.. So for existence, on the wiki index page, I only see...

Error: Macro TitleIndex(format=group,min=4) failed
coercing to Unicode: need string or buffer, NoneType found

After I disable it under admin, macros work fine again. I've also successfully run GraphVizPlugin on previous 0.11.x installations.

Details of my setup include OS X 10.5.5 with the stock Apache 2.2.9 and Python 2.5.1 ... mod_wsgi 2.3 and dot installed to '/usr/local/bin'

[Eli Carter]

This appears to be related to antialiasing. I commented out the png_antialias = true option in the [graphviz] section, and it worked again. I get a different error if rsvg is installed and rsvg_path is set; so there is still something amiss.

[Christian Boos]

I probably get rid of the png_antialias option in future releases, as I think this is not necessary anymore (#737).

Still, it seems quite mysterious that a problem with this can propagate to the TitleIndex macro... which version of the GraphvizPlugin was this?

Does that still happen with graphvizplugin/0.11-0.7.5? If yes, can you share all the settings needed for being able to reproduce this? (in addition to what you've already given, the trac.ini settings and the page content).