I have a Linux Mint 18.1 Serena installed, and the apt-get install ring won't do the trick. it returns the following:Some packages could not be installed. This may mean that you haverequested an impossible situation or if you are using the unstabledistribution that some required packages have not yet been createdor been moved out of Incoming.The following information may help to resolve the situation:The following packages have unmet dependencies: ring : Depends: libedataserver-1.2-22 (>= 3.17) but it is not installable        Depends: libqt5core5a (>= 5.6.0~beta) but 5.5.1+dfsg-16ubuntu7.2 is to be installed        Depends: ring-daemon (= 20161228.1.49686a5~dfsg1-1) but it is not going to be installedE: Unable to correct problems, you have held broken packages.Then I tried:apt-get clean & updateaptitude -f install ringapt-get install ring --fix-brokenBut, it didn't help to resolve this problem. How to solve?The output of apt-cache policy ring:ring:  Installed: (none)  Candidate: 20161228.1.49686a5~dfsg1-1  Version table:     20161228.1.49686a5~dfsg1-1 500        500 https://dl.ring.cx/ring-nightly/ubuntu_16.10 ring/main amd64 Packagessudo aptitude: 
Broken package problem installing ring on Mint 18.1
linux mint;apt;package management;aptitude;voip
From this announcement, Linux Mint 18.1 is supported until 2021 and is based on Ubuntu 16.04 LTS.Judging by the result of your apt-cache policy ring command, your ring package was built for Ubuntu 16.10. This is no surprise then that some dependencies to ring are missing on your system (or, rather, are available but not with the expected version).The solution is to install ring for Ubuntu 16.04. You must modify the ring repositories you have set up, by changing https://dl.ring.cx/ring-nightly/ubuntu_16.10 to https://dl.ring.cx/ring-nightly/ubuntu_16.04