python-wxgtk-media3.0 is wxPython Classic, not Phoenix and is built against GTK+ 2, not GTK+ 3 in Debian/Ubuntu. That's why libgtk-3-dev is not a build dependency.
BTW, wxPython Phoenix will be included in Bionic. ** Changed in: wxpython3.0 (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1755025 Title: add libgtk-3-dev to python-wxgtk-media3.0 build-deps To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/wxpython3.0/+bug/1755025/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs