https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66847
--- Comment #4 from DB <db0451 at gmail dot com> ---
It should be noted that although I have a commented-out {brace} ctor for the
final class in main(), that was just a test; both {brace} and (parenthesis)
init in that context produce the same behaviour. That is: dependent upon the
type of braces used by Derived to call Base ctor.
