|These instructions are for the Qt4-based Calligra 2.x on Unix and similar operating systems. These instruction won't be extended much as development of the Qt4-based Calligra ends with the 2.9 series.|
Be patient, opening Calligra can take a long time, KDevelop don't show any progress information, only indication that something is happening is an overlay telling you the project is being loaded, and the "projects" docker has appeared
In the "project" docker, browse to the target you want to build, right click on it, and select "build" or "install". You can add a target to the buildset, all target in the buildset will be build when pressing F8, or any of the other options of the "Build" menu.
Run target are easily change through "Run > Current Run Target"