Source-built engine compiles all every time -> Takes long

Hey guys,
I went ahead and cloned the Unreal Engine 4.9.2 release from GitHub today and ran Setup.bat and GenerateProjectFiles.bat, Nice, then I built the editor once (took around 45 mins D:). Everything fine. I created with my source-built version one new project (I want to create a dedicated server in this test project). I created the project, did literally nothing in it, packaged it. it seems like he rebuilt all the cpps out of the UE4 project again, so packaging my game did finally take up 30 mins… I thought maybe its the first time doing that. Same with dedicated Server. Built it (with Instructions from the wiki) and it went ahead and builded every god ■■■■ CPP out of UE4 project again. It says something with Performing 230 tasks [4 in parralel]. So when I made an error in the config (default load level on the server), I needed to rebuild the server. I thought, hmm, maybe he will just go ahead and take the already built engine from the last compile and just does the server, but no. Is this for real? I mean, do I need to wait everytime I want to compile my Client/Server till everything from UE4 compiled. That takes up so much time :frowning: