.la files weren't supposed to be removed until they weren't used anymore (Debian's GTK+ still provides this) so either the .la file needs to be put back in libgtk+2.0-dev or python-visual needs to be changed not to need it.
.la files weren't supposed to be removed until they weren't used anymore (Debian's GTK+ still provides this) so either the .la file needs to be put back in libgtk+2.0-dev or python-visual needs to be changed not to need it.