The following packages have unmet dependencies:
libatk-bridge2.0-dev : Depends: libatk-bridge2.0-0 (= 2.46.0-5) but 2.50.0-1~bpo12+1 is to be installed
Depends: libatspi2.0-dev but it is not going to be installed
libatk1.0-dev : Depends: libatk1.0-0 (= 2.46.0-5) but 2.50.0-1~bpo12+1 is to be installed
Depends: gir1.2-atk-1.0 (= 2.46.0-5) but 2.50.0-1~bpo12+1 is to be installed
E: Unable to correct problems, you have held broken packages.