tsonic uses NativeAOT by default, and DLR/System.Dynamic isn't supported in NativeAOT. There are switches in tsonic to give you MSIL, but that's used mostly for

tsonic uses NativeAOT by default, and DLR/System.Dynamic isn't supported in NativeAOT. There are switches in tsonic to give you MSIL, but that's used mostly for testing or for compat reasons.