/usr/include/gecode/kernel/ is in libgecode-dev 4.4.0-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gecode/kernel/activity.hpp
/usr/include/gecode/kernel/advisor.hpp
/usr/include/gecode/kernel/afc.hpp
/usr/include/gecode/kernel/allocators.hpp
/usr/include/gecode/kernel/archive.hpp
/usr/include/gecode/kernel/array.hpp
/usr/include/gecode/kernel/branch-tiebreak.hpp
/usr/include/gecode/kernel/branch-traits.hpp
/usr/include/gecode/kernel/branch-val.hpp
/usr/include/gecode/kernel/branch-var.hpp
/usr/include/gecode/kernel/brancher-merit.hpp
/usr/include/gecode/kernel/brancher-val-commit.hpp
/usr/include/gecode/kernel/brancher-val-sel-commit.hpp
/usr/include/gecode/kernel/brancher-val-sel.hpp
/usr/include/gecode/kernel/brancher-view-sel.hpp
/usr/include/gecode/kernel/brancher-view-val.hpp
/usr/include/gecode/kernel/brancher-view.hpp
/usr/include/gecode/kernel/core.hpp
/usr/include/gecode/kernel/exception.hpp
/usr/include/gecode/kernel/global-afc.hpp
/usr/include/gecode/kernel/macros.hpp
/usr/include/gecode/kernel/memory-config.hpp
/usr/include/gecode/kernel/memory-manager.hpp
/usr/include/gecode/kernel/modevent.hpp
/usr/include/gecode/kernel/propagator.hpp
/usr/include/gecode/kernel/range-list.hpp
/usr/include/gecode/kernel/region.hpp
/usr/include/gecode/kernel/rnd.hpp
/usr/include/gecode/kernel/shared-array.hpp
/usr/include/gecode/kernel/var-imp.hpp
/usr/include/gecode/kernel/var-type.hpp
/usr/include/gecode/kernel/var.hpp
/usr/include/gecode/kernel/view.hpp
/usr/include/gecode/kernel/wait.hh