/usr/include/gpaste/ is in libgpaste2-dev 3.14-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gpaste/gpaste-applet-about.h
/usr/include/gpaste/gpaste-applet-delete.h
/usr/include/gpaste/gpaste-applet-empty.h
/usr/include/gpaste/gpaste-applet-footer.h
/usr/include/gpaste/gpaste-applet-header.h
/usr/include/gpaste/gpaste-applet-history.h
/usr/include/gpaste/gpaste-applet-icon.h
/usr/include/gpaste/gpaste-applet-item.h
/usr/include/gpaste/gpaste-applet-menu.h
/usr/include/gpaste/gpaste-applet-quit.h
/usr/include/gpaste/gpaste-applet-settings.h
/usr/include/gpaste/gpaste-applet-status-icon.h
/usr/include/gpaste/gpaste-applet-switch.h
/usr/include/gpaste/gpaste-applet.h
/usr/include/gpaste/gpaste-client.h
/usr/include/gpaste/gpaste-clipboard.h
/usr/include/gpaste/gpaste-clipboards-manager.h
/usr/include/gpaste/gpaste-config.h
/usr/include/gpaste/gpaste-daemon.h
/usr/include/gpaste/gpaste-gdbus-defines.h
/usr/include/gpaste/gpaste-gnome-shell-client.h
/usr/include/gpaste/gpaste-gsettings-keys.h
/usr/include/gpaste/gpaste-history.h
/usr/include/gpaste/gpaste-image-item.h
/usr/include/gpaste/gpaste-item.h
/usr/include/gpaste/gpaste-keybinder.h
/usr/include/gpaste/gpaste-keybinding.h
/usr/include/gpaste/gpaste-macros.h
/usr/include/gpaste/gpaste-make-password-keybinding.h
/usr/include/gpaste/gpaste-password-item.h
/usr/include/gpaste/gpaste-pop-keybinding.h
/usr/include/gpaste/gpaste-settings-ui-panel.h
/usr/include/gpaste/gpaste-settings-ui-stack.h
/usr/include/gpaste/gpaste-settings-ui-widget.h
/usr/include/gpaste/gpaste-settings.h
/usr/include/gpaste/gpaste-show-history-keybinding.h
/usr/include/gpaste/gpaste-sync-clipboard-to-primary-keybinding.h
/usr/include/gpaste/gpaste-sync-primary-to-clipboard-keybinding.h
/usr/include/gpaste/gpaste-text-item.h
/usr/include/gpaste/gpaste-update-enums.h
/usr/include/gpaste/gpaste-uris-item.h
/usr/include/gpaste/gpaste.h