/usr/lib/gcl-2.6.12/gcl-tk/ is in gcl 2.6.12-29.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/gcl-2.6.12/gcl-tk/decode.tcl
/usr/lib/gcl-2.6.12/gcl-tk/demos/
/usr/lib/gcl-2.6.12/gcl-tk/demos/gc-monitor.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/index.lsp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkBasic.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkCanvText.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkEntry.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkEntry2.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkForm.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkHScale.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkItems.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkLabel.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkListbox.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkPlot.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkRadio.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkRuler.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkSearch.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkStyles.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkTextBind.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkVScale.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/mkdialog.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/nqthm-stack.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/showVars.lisp
/usr/lib/gcl-2.6.12/gcl-tk/demos/widget.lisp
/usr/lib/gcl-2.6.12/gcl-tk/gcl.tcl
/usr/lib/gcl-2.6.12/gcl-tk/tk-package.lsp