D-Programming-Language/dmd — pull request #3645 by 9rnsr (2014-06-08 01:35:07+00:00)
Title: Issue 12825 - Invalid "duplicated union initialization" error with initialized field in extern(C++) class

https://issues.dlang.org/show_bug.cgi?id=12825

It's a mismatch between front-end and glue layer.