There is another problem:
python-dbus-dev requires libdbus-1-dev but does NOT depend on it, or at least pkg-config thinks so, so configure thinks it's not there.
pkg-config --cflags dbus-python # Package dbus-1 was not found...
sudo apt-get install libdbus-1-dev
pkg-config --cflags dbus-python # -I/usr/include/......
Once I do this, the synctex plugin builds.
There is another problem:
python-dbus-dev requires libdbus-1-dev but does NOT depend on it, or at least pkg-config thinks so, so configure thinks it's not there.
pkg-config --cflags dbus-python
# Package dbus-1 was not found...
sudo apt-get install libdbus-1-dev
pkg-config --cflags dbus-python include/ ......
# -I/usr/
Once I do this, the synctex plugin builds.