/usr/include/libpeas-1.0/libpeas/ is in libpeas-dev 1.8.1-2ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libpeas-1.0/libpeas-gtk/peas-gtk-configurable.h
/usr/include/libpeas-1.0/libpeas-gtk/peas-gtk-plugin-manager-view.h
/usr/include/libpeas-1.0/libpeas-gtk/peas-gtk-plugin-manager.h
/usr/include/libpeas-1.0/libpeas-gtk/peas-gtk.h
/usr/include/libpeas-1.0/libpeas/peas-activatable.h
/usr/include/libpeas-1.0/libpeas/peas-engine.h
/usr/include/libpeas-1.0/libpeas/peas-extension-base.h
/usr/include/libpeas-1.0/libpeas/peas-extension-set.h
/usr/include/libpeas-1.0/libpeas/peas-extension.h
/usr/include/libpeas-1.0/libpeas/peas-object-module.h
/usr/include/libpeas-1.0/libpeas/peas-plugin-info.h
/usr/include/libpeas-1.0/libpeas/peas.h