Error while running apt-build-dep on repository

Hi,
I'm building the ownCloud client on Ubuntu 16.04. I'm following the steps here. While running apt-get build-dep owncloud-client , I get this error:

The following packages have unmet dependencies:
builddeps:owncloud-client : Depends: ocqt562-qt5-qmake but it is not installable
Depends: ocqt562-qttools5-dev-tools but it is not installable
Depends: ocqt562-qtbase5-dev but it is not installable
Depends: ocqt562-qt5keychain-dev (>= 0.7.0) but it is not installable
Depends: ocqt562-libqt5webkit5-dev (>= 2.2.0) but it is not installable
E: Unable to correct problems, you have held broken packages.

I checked the repository, and it has those *.deb packages present for amd64(my PC). Even apt-get install owncloud-client works correctly.

My sources.list.d/owncloud-client.list file looks like this:
deb-src http://download.opensuse.org/repositories/isv:/ownCloud:/desktop/Ubuntu_16.04/ /

Thanks for your help