libindicator3-dev depends on libgtk-3-dev, and it appears it is not installable in parallel for two architectures:
$ sudo apt install libgtk-3-dev:amd64 libgtk-3-dev:i386 Reading package lists... Done Building dependency tree Reading state information... Done libgtk-3-dev is already the newest version (3.22.28-1ubuntu3). Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation: The following packages have unmet dependencies: libgtk-3-dev:i386 : Depends: libgdk-pixbuf2.0-dev:i386 (>= 2.30.0) but it is not going to be installed Depends: libpango1.0-dev:i386 (>= 1.40.5) but it is not going to be installed Depends: libegl1-mesa-dev:i386 but it is not going to be installed Depends: libxkbcommon-dev:i386 but it is not going to be installed E: Unable to correct problems, you have held broken packages. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1757204 Title: libindicator is not multi-arch aware To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libindicator/+bug/1757204/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs