Maintainers for graphviz are Laszlo Boszormenyi (GCS) <gcs@debian.org>.
You may want to refer to the following individual bug pages: graphviz-doc, graphviz-tools, libcdt-dev, libcdt5, libcgraph-dev, libcgraph6, libgraphviz-dev, libgv-guile, libgv-lua, libgv-perl, libgv-php7, libgv-ruby, libgv-tcl, libgvc-dev, libgvc6, libgvc6-plugins-gtk, libgvplugin-devil, libgvplugin-devil-dev, libgvplugin-gd, libgvplugin-gd-dev, libgvplugin-gs, libgvplugin-gs-dev, libgvplugin-neato-layout, libgvplugin-neato-layout-dev, libgvplugin-pango, libgvplugin-pango-dev, libgvplugin-poppler, libgvplugin-poppler-dev, libgvplugin-rsvg, libgvplugin-rsvg-dev, libgvplugin-vt, libgvplugin-vt-dev, libgvplugin-vt100, libgvplugin-vt100-dev, libgvplugin-webp, libgvplugin-webp-dev, libgvplugin-xlib, libgvplugin-xlib-dev, libgvpr-dev, libgvpr2, liblab-gamut1, libpathplan-dev, libpathplan4, libxdot-dev, libxdot4, python-gv, python3-gv, tcl-gv.
You might like to refer to the graphviz package page, or to the Package Tracking System.
If you find a bug not listed here, please report it.