Development Guide

Setting up Eclipse

Clone mylyn-gitlab git repository into a directory.
In Eclipse choose, File > Import... > Maven > Existing Maven Projects.
Set the Root Directory to the root of the mylyn-gitlab repository where pom.xml is located (there are several but this is the parent). Make sure all pom.xml files are checked. Choose Next and then Finish.
There will be a prompt to install the Tycho Project Configurators plugin. Install it.
If you open the Plug-in Development perspective you should see the different projects in the Package Folder.

de.weingardt.mylyn.gitlab.updatesite is the eclipse update site project which builds the eclipse repository for gh-pages.
de.weingardt.mylyn.gitlab.core is part of the plugin. It is the logic of the MVC.
de.weingardt.mylyn.gitlab.ui is part of the plugin. It is the User Interface or View of the MVC.
de.weingardt.mylyn.gitlab is contains meta information and package details when the package is built.
de.weingardt.mylyn.gitlab-parent is where the plugin package is built.

Right click on de.weingardt.mylyn.gitlab-parent and choose Run As > Maven build.
Enter clean verify into the Goals text field.
Click Run.

You don't need to build the Maven project to test it. You can inject the plugin into a runtime Eclipse.

In the Package Folder right click on de.weingardt.mylyn.gitlab.ui. Choose Run As > Eclipse Application.
Start interacting with the runtime Eclipse because it will have the newly built plugin injected in the runtime.