configure: error:

  Tcl cannot be found on this system.

  Eggdrop requires Tcl to compile. If you already have Tcl installed on
  this system, and I just wasn't looking in the right place for it, re-run
  ./configure using the --with-tcllib='/path/to/libtcl.so' and
  --with-tclinc='/path/to/tcl.h' options.

  See doc/COMPILE-GUIDE's 'Tcl Detection and Installation' section for more
  information.