I get this whether building from the CLI or via the GUI, but here's the CLI output:
Building package (de): product.msi
Preparing files... done.
Creating CAB file(s)... done.
Creating MSI database... done.
Inserting CAB file(s) into MSI... done.
Writing Summary Information... done.
At that point in every generation of the language-specific MSI's, I get a Visual Studio dialog (see attached). I'm pretty sure it's the Visual Studio 2013 package self-repairing itself. It eventually goes away on its own, but it definitely slows down my build process.
Anybody else seeing this?