kchmviewer - configure fails - conditional "include_x11" was never defined

All, kchmviewer fails during configure. The error is a strange conditional definition error in the configure file that I haven't run across before. The error is: chmlib to link : system checking if lib should be compiled... yes checking if po should be compiled... yes checking if src should be compiled... yes checking that generated files are newer than configure... done configure: error: conditional "include_x11" was never defined. Usually this means the macro was only invoked conditionally. From the error it looks like the "include_x11" was used in a conditional but not previously defined (or something like that). If you are familiar with 'configure' define statements, or this error, then please let me know your thoughts on fixing it. I'll begin picking through it in the mean time. -- David C. Rankin, J.D.,P.E.