I did not actively search for the subject, but once I bumped into a three-part article about the MSBuild script debugging (Part I, Part II, Part III) on The Visual Studio Blog I immediately though that it is worth remembering about it when (I am not saying if, but rather when here) I need it in the future. The blog itself is also worth checking, as there is much information about VS IDE, MSBuild, and extensibility from the Visual Studio development team.