UE4 build from source stalled

Hi. I’m building UE4 from source. I’ve clicked build, but its more than 1.5 hours there are no outputs about anything. But before, when I did it through REBUILD button, it showed all outputs correctly, now it doesn’t, which makes think is build running or not, and how to make it show outputs.

It states “Building UE4Editor and ShaderCompileWorker…”, progress bar doesn’t show even 1 percent, day ago when I rebuild it, build had started after 1 hour of cleaning and rebuilding UnrealHeaderTool.

What is going on? How to resolve this issue? Thanks