Ah, dragndrop seems broken on system-configuration
"sparc-sun-solaris2.5.1".
Without it I built successfully (see below).
Adrian
XEmacs Build Report as generated
by build-report-version $Revision: 1.39 $ follows:
Contents of /export/home/tmp/xemacs-21.0-b39/Installation:
(Output from most recent run of ./configure)