anchor.diff:  , srcRepo ? false, autoreconfHook ? null, texinfo ? null
   , siteStart ? ./site-start.el
   , nativeComp ? false
  +, withAthena ? false
  +, withToolkitScrollBars ? true
   , withPgtk ? false
   , withXinput2 ? false
   , withImageMagick ? lib.versionOlder version "27" && (withX || withNS)
  
positive.code:     ++ lib.optional withImageMagick "--with-imagemagick"
      ++ lib.optional withPgtk "--with-pgtk"
      ++ lib.optional withXinput2 "--with-xinput2"
    ;
  
    installTargets = [ "tags" "install" ];
  
negative.code:   if withGTK2 then "gtk2"
    else if withGTK3 then "gtk3"
    else if withMotif then "motif"
    else if withAthena then "athena"
    else "lucid")
  }:
  
  