The following packages have unmet dependencies:

root@ubuntu:~# apt-get install open-iscsi
Reading package lists... Done
Building dependency tree
Reading state information... Done
open-iscsi is already the newest version (2.0.873+git0.3b4b4500-14ubuntu3.4).
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
virtualbox-5.2 : Depends: libcurl3 (>= 7.16.2) but it is not going to be installed
Depends: libfontconfig1 (>= 2.11.94) but it is not going to be installed
Depends: libgl1-mesa-glx but it is not going to be installed or
libgl1
Depends: libice6 (>= 1:1.0.0) but it is not going to be installed
Depends: libsdl1.2debian (>= 1.2.11) but it is not going to be installed
Depends: libsm6 but it is not going to be installed
Depends: libvpx3 (>= 1.5.0) but it is not going to be installed
Depends: libx11-xcb1 but it is not going to be installed
Depends: libxcursor1 (> 1.1.2) but it is not going to be installed
Depends: libxinerama1 but it is not going to be installed
Depends: libxmu6 but it is not going to be installed
Depends: libxrender1 but it is not going to be installed
Depends: libxt6 but it is not going to be installed
Recommends: libasound2
Recommends: libpulse0 but it is not going to be installed
Recommends: libsdl-ttf2.0-0 but it is not going to be installed
Recommends: gcc but it is not going to be installed
Recommends: make or
build-essential but it is not going to be installed or
dpkg-dev but it is not going to be installed
Recommends: binutils but it is not going to be installed
Recommends: pdf-viewer
Recommends: libgl1
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

root@ubuntu:~# dpkg --purge virtualbox-5.2
(Reading database ... 61116 files and directories currently installed.)
Removing virtualbox-5.2 (5.2.14-123301~Ubuntu~xenial) ...
Purging configuration files for virtualbox-5.2 (5.2.14-123301~Ubuntu~xenial) ...
Processing triggers for libc-bin (2.23-0ubuntu10) ...
Processing triggers for mime-support (3.59ubuntu1) ...
Processing triggers for shared-mime-info (1.5-2ubuntu0.1) ...