XmMessageBoxGetChild(3) on Linux
The text 33ea28c9820f, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A MessageBox function that is used to access a component "XmMessageBoxGetChild" "MessageBox functions" "XmMessageBoxGetChild"