Crazy rebuilding with UE4.5: rebuilds all DLLS ("[n/266]")

We’ve been using UE4 for about a year now. The moment we integrated with UE4.5, I suddenly started experiencing crazy rebuild times for every single code change, and I have no idea why.

My teammates are not having this problem, even though they have identical build configurations.

I even deleted my .sln, .sdf, and .suo files and did a “Generate Visual Studio Project Files” again, and that didn’t fix it either.

Even simply hitting F7 with zero code changes causes it to go through all 266 rebuild steps of rebuilding the engine DLLs (see attached text file).link text

Never mind – this was a bug with Perforce; we are building from source and P4 has some real issues with directories whose contents are above a certain size.