A few potential bug reports: https://issues.dlang.org/show_bug.cgi?id=22161 https://issues.dlang.org/show_bug.cgi?id=23725 https://issues.dlang.org/show_bug.cgi?id=22722 It may also be required if we want out of the box support on Windows, as the mingw headers also use inline assembly (which errors out).