/usr/share/common-lisp/source/ is in cl-contextl 1:0.61-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/common-lisp/source/contextl/
/usr/share/common-lisp/source/contextl/contextl-packages.lisp
/usr/share/common-lisp/source/contextl/contextl.asd
/usr/share/common-lisp/source/contextl/cx-class-in-layer.lisp
/usr/share/common-lisp/source/contextl/cx-dynamic-environments.lisp
/usr/share/common-lisp/source/contextl/cx-dynamic-variables.lisp
/usr/share/common-lisp/source/contextl/cx-dynascope.lisp
/usr/share/common-lisp/source/contextl/cx-gc.lisp
/usr/share/common-lisp/source/contextl/cx-layer-metaclasses.lisp
/usr/share/common-lisp/source/contextl/cx-layer.lisp
/usr/share/common-lisp/source/contextl/cx-layered-access-class.lisp
/usr/share/common-lisp/source/contextl/cx-layered-class.lisp
/usr/share/common-lisp/source/contextl/cx-layered-function-macros.lisp
/usr/share/common-lisp/source/contextl/cx-layered-function.lisp
/usr/share/common-lisp/source/contextl/cx-partial-class.lisp
/usr/share/common-lisp/source/contextl/cx-singleton-class.lisp
/usr/share/common-lisp/source/contextl/cx-special-class.lisp
/usr/share/common-lisp/source/contextl/cx-threads.lisp
/usr/share/common-lisp/source/contextl/cx-util.lisp
/usr/share/common-lisp/source/contextl/dynamic-wind-packages.lisp
/usr/share/common-lisp/source/contextl/dynamic-wind.asd