/usr/include/libabigail/ is in libabigail-dev 1.0~rc6-1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libabigail/abg-comp-filter.h
/usr/include/libabigail/abg-comparison.h
/usr/include/libabigail/abg-config.h
/usr/include/libabigail/abg-corpus.h
/usr/include/libabigail/abg-diff-utils.h
/usr/include/libabigail/abg-dwarf-reader.h
/usr/include/libabigail/abg-fwd.h
/usr/include/libabigail/abg-hash.h
/usr/include/libabigail/abg-ini.h
/usr/include/libabigail/abg-interned-str.h
/usr/include/libabigail/abg-ir.h
/usr/include/libabigail/abg-libxml-utils.h
/usr/include/libabigail/abg-libzip-utils.h
/usr/include/libabigail/abg-reader.h
/usr/include/libabigail/abg-sptr-utils.h
/usr/include/libabigail/abg-suppression.h
/usr/include/libabigail/abg-tools-utils.h
/usr/include/libabigail/abg-traverse.h
/usr/include/libabigail/abg-version.h
/usr/include/libabigail/abg-viz-common.h
/usr/include/libabigail/abg-viz-dot.h
/usr/include/libabigail/abg-viz-svg.h
/usr/include/libabigail/abg-workers.h
/usr/include/libabigail/abg-writer.h