anchor.diff:  , libjpeg
   , libpng
   , libtiff
  +, zlib
   
   , channel
   }:
  
positive.code:     libjpeg
      libpng
      libtiff
    ];
  
    configureFlags = [
  
negative.code:     "--enable-man"
      "--${boolEn (gobject-introspection != null)}-introspection"
      "--${boolWt (libjpeg != null)}-libjpeg"
      "--${boolWt (libtiff != null && zlib != null)}-libtiff"
      "--${boolWt (lcms2 != null)}-liblcms2"
    ];
  
  