/usr/lib/ is in ikarus 0.0.3+bzr.2010.01.26-4ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/ikarus/
/usr/lib/x86_64-linux-gnu/ikarus/Cocoa/
/usr/lib/x86_64-linux-gnu/ikarus/Cocoa/helpers.ss
/usr/lib/x86_64-linux-gnu/ikarus/Cocoa.ss
/usr/lib/x86_64-linux-gnu/ikarus/flonum-formatter.sls
/usr/lib/x86_64-linux-gnu/ikarus/flonum-parser.sls
/usr/lib/x86_64-linux-gnu/ikarus/foreign.ss
/usr/lib/x86_64-linux-gnu/ikarus/gl.ss
/usr/lib/x86_64-linux-gnu/ikarus/glut.ss
/usr/lib/x86_64-linux-gnu/ikarus/ikarus.boot
/usr/lib/x86_64-linux-gnu/ikarus/include.ss
/usr/lib/x86_64-linux-gnu/ikarus/ipc.ss
/usr/lib/x86_64-linux-gnu/ikarus/match.ss
/usr/lib/x86_64-linux-gnu/ikarus/objc.ss
/usr/lib/x86_64-linux-gnu/ikarus/ypsilon-compat.ikarus.ss
/usr/lib/x86_64-linux-gnu/ikarus/ypsilon-compat.ypsilon.ss