I must be doing something wrong. I’ve just started messing around with c++, and the build times are KILLING me…
Just now, I went to launch an instance of UE4 and it’s rebuilding it all again. Been here for 30 minutes just waiting. I’ve launched instances plenty of times before this. Why now? Sometimes this happens, sometimes not. This also happen when I’m building projects. Sometimes it’s fast, and sometimes I sit there for 30 minutes quietly fuming…
Are you using the UE4 binary or building from github source?
If the latter, I’ve seen what you described on a few occasions and I use "Build–>Project Only–>Build Only %MyProjectName% to ensure that the engine source isn’t being rebuilt along with project source.