/usr/include/ is in libdawgdic-dev 0.4.5-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/dawgdic/
/usr/include/dawgdic/link-table.h
/usr/include/dawgdic/dawg.h
/usr/include/dawgdic/dictionary-unit.h
/usr/include/dawgdic/ranked-completer.h
/usr/include/dawgdic/completer.h
/usr/include/dawgdic/ranked-guide-link.h
/usr/include/dawgdic/dawg-unit.h
/usr/include/dawgdic/dictionary.h
/usr/include/dawgdic/guide-builder.h
/usr/include/dawgdic/ranked-guide-unit.h
/usr/include/dawgdic/guide-unit.h
/usr/include/dawgdic/ranked-completer-candidate.h
/usr/include/dawgdic/object-pool.h
/usr/include/dawgdic/ranked-completer-node.h
/usr/include/dawgdic/ranked-guide.h
/usr/include/dawgdic/base-unit.h
/usr/include/dawgdic/dictionary-extra-unit.h
/usr/include/dawgdic/ranked-guide-builder.h
/usr/include/dawgdic/guide.h
/usr/include/dawgdic/dawg-builder.h
/usr/include/dawgdic/bit-pool.h
/usr/include/dawgdic/base-types.h
/usr/include/dawgdic/dictionary-builder.h