@sylveon long story... when I first built C++/WinRT and the DX library before it, the put functions were used heavily by the projection itself for binding ABI calls under the hood and injecting the cleanup code into every callsite was prohibitive. Today, C++/WinRT doesn't use those interop functions internally very much and its mainly used by app-level interop code where developers expect more from such helpers.

The build actually succeeded - seems to be a mix of Azure build and GitHub reporting issues.