/usr/share/common-lisp/source/ is in cl-memstore 1.1.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/common-lisp/source/memstore/
/usr/share/common-lisp/source/memstore/memcache/
/usr/share/common-lisp/source/memstore/memcache/compat.lisp
/usr/share/common-lisp/source/memstore/memcache/memcache.lisp
/usr/share/common-lisp/source/memstore/memcache/package.lisp
/usr/share/common-lisp/source/memstore/memcache/specials.lisp
/usr/share/common-lisp/source/memstore/memcache/util.lisp
/usr/share/common-lisp/source/memstore/src/
/usr/share/common-lisp/source/memstore/src/compress.lisp
/usr/share/common-lisp/source/memstore/src/memstore.lisp
/usr/share/common-lisp/source/memstore/src/package.lisp
/usr/share/common-lisp/source/memstore/src/tests.lisp