SolutionPackager not including Formulas

Hi all,

We are having a problem with SolutionPackager where it does not export or import Formulas (calculated fields) folder under the solution. We can see it in the zip file but its not getting extracted. The only workaround is to manually extract from zip file Formulas folder and also manually add it back when Visual Studio is done building. Anyone else has this problem?

I have tried 2016 SDK and it has the same problem. Is SolutionPackager source code available somewhere? If not why not?

Thanks!