Why doesn the scrollbar work?
Originally xterm was built using imake rather than a configure script. One feature of imake that is not possible to guess within the configure script is the wide-prototype compile-time definition NARROWPROTO. When this is not set properly, the Athena widget scrollbars do not work properly. xterm’s configure script has a fallback case which allows disabling imake. However, this is moot with the Xorg “modular” build, whose compiler options are unrelated to imake or older versions of any libraries that it may distribute. In this case, the configure script needs some help. Use this option to enable or disable NARROW proto (and disable imake with the –disable-imake option) to match the whims of Xorg hackers.