/usr/ is in libbox2d-dev 2.3.1+ds-3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/box2d.pc
/usr/lib/x86_64-linux-gnu/libBox2D.a
/usr/lib/x86_64-linux-gnu/cmake/
/usr/lib/x86_64-linux-gnu/cmake/Box2D/
/usr/lib/x86_64-linux-gnu/cmake/Box2D/Box2DConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/Box2D/UseBox2D.cmake
/usr/lib/x86_64-linux-gnu/Box2D/
/usr/lib/x86_64-linux-gnu/Box2D/Box2D-targets.cmake
/usr/lib/x86_64-linux-gnu/Box2D/Box2D-targets-none.cmake
/usr/share/
/usr/share/doc/
/usr/share/doc/libbox2d-dev/
/usr/share/doc/libbox2d-dev/copyright
/usr/include/
/usr/include/Box2D/
/usr/include/Box2D/Common/
/usr/include/Box2D/Common/b2Draw.h
/usr/include/Box2D/Common/b2BlockAllocator.h
/usr/include/Box2D/Common/b2Settings.h
/usr/include/Box2D/Common/b2GrowableStack.h
/usr/include/Box2D/Common/b2Math.h
/usr/include/Box2D/Common/b2Timer.h
/usr/include/Box2D/Common/b2StackAllocator.h
/usr/include/Box2D/Box2D.h
/usr/include/Box2D/Rope/
/usr/include/Box2D/Rope/b2Rope.h
/usr/include/Box2D/Collision/
/usr/include/Box2D/Collision/b2TimeOfImpact.h
/usr/include/Box2D/Collision/b2Collision.h
/usr/include/Box2D/Collision/b2BroadPhase.h
/usr/include/Box2D/Collision/b2DynamicTree.h
/usr/include/Box2D/Collision/Shapes/
/usr/include/Box2D/Collision/Shapes/b2PolygonShape.h
/usr/include/Box2D/Collision/Shapes/b2Shape.h
/usr/include/Box2D/Collision/Shapes/b2CircleShape.h
/usr/include/Box2D/Collision/Shapes/b2EdgeShape.h
/usr/include/Box2D/Collision/Shapes/b2ChainShape.h
/usr/include/Box2D/Collision/b2Distance.h
/usr/include/Box2D/Dynamics/
/usr/include/Box2D/Dynamics/b2ContactManager.h
/usr/include/Box2D/Dynamics/b2World.h
/usr/include/Box2D/Dynamics/Contacts/
/usr/include/Box2D/Dynamics/Contacts/b2PolygonContact.h
/usr/include/Box2D/Dynamics/Contacts/b2EdgeAndCircleContact.h
/usr/include/Box2D/Dynamics/Contacts/b2EdgeAndPolygonContact.h
/usr/include/Box2D/Dynamics/Contacts/b2Contact.h
/usr/include/Box2D/Dynamics/Contacts/b2ChainAndCircleContact.h
/usr/include/Box2D/Dynamics/Contacts/b2ContactSolver.h
/usr/include/Box2D/Dynamics/Contacts/b2ChainAndPolygonContact.h
/usr/include/Box2D/Dynamics/Contacts/b2PolygonAndCircleContact.h
/usr/include/Box2D/Dynamics/Contacts/b2CircleContact.h
/usr/include/Box2D/Dynamics/b2Body.h
/usr/include/Box2D/Dynamics/b2Island.h
/usr/include/Box2D/Dynamics/b2WorldCallbacks.h
/usr/include/Box2D/Dynamics/b2Fixture.h
/usr/include/Box2D/Dynamics/b2TimeStep.h
/usr/include/Box2D/Dynamics/Joints/
/usr/include/Box2D/Dynamics/Joints/b2WheelJoint.h
/usr/include/Box2D/Dynamics/Joints/b2WeldJoint.h
/usr/include/Box2D/Dynamics/Joints/b2FrictionJoint.h
/usr/include/Box2D/Dynamics/Joints/b2PrismaticJoint.h
/usr/include/Box2D/Dynamics/Joints/b2RevoluteJoint.h
/usr/include/Box2D/Dynamics/Joints/b2MouseJoint.h
/usr/include/Box2D/Dynamics/Joints/b2MotorJoint.h
/usr/include/Box2D/Dynamics/Joints/b2Joint.h
/usr/include/Box2D/Dynamics/Joints/b2GearJoint.h
/usr/include/Box2D/Dynamics/Joints/b2PulleyJoint.h
/usr/include/Box2D/Dynamics/Joints/b2RopeJoint.h
/usr/include/Box2D/Dynamics/Joints/b2DistanceJoint.h
/usr/lib/x86_64-linux-gnu/libBox2D.so
/usr/share/doc/libbox2d-dev/changelog.Debian.gz