/usr/include/sbuild/ is in libsbuild-dev 1.6.10-1ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/sbuild/sbuild-auth-null.h
/usr/include/sbuild/sbuild-auth-pam-conv-tty.h
/usr/include/sbuild/sbuild-auth-pam-conv.h
/usr/include/sbuild/sbuild-auth-pam-message.h
/usr/include/sbuild/sbuild-auth-pam.h
/usr/include/sbuild/sbuild-auth.h
/usr/include/sbuild/sbuild-basic-keyfile.h
/usr/include/sbuild/sbuild-basic-keyfile.tcc
/usr/include/sbuild/sbuild-chroot-block-device-base.h
/usr/include/sbuild/sbuild-chroot-block-device.h
/usr/include/sbuild/sbuild-chroot-btrfs-snapshot.h
/usr/include/sbuild/sbuild-chroot-config.h
/usr/include/sbuild/sbuild-chroot-custom.h
/usr/include/sbuild/sbuild-chroot-directory-base.h
/usr/include/sbuild/sbuild-chroot-directory.h
/usr/include/sbuild/sbuild-chroot-facet-mountable.h
/usr/include/sbuild/sbuild-chroot-facet-personality.h
/usr/include/sbuild/sbuild-chroot-facet-session-clonable.h
/usr/include/sbuild/sbuild-chroot-facet-session.h
/usr/include/sbuild/sbuild-chroot-facet-source-clonable.h
/usr/include/sbuild/sbuild-chroot-facet-source.h
/usr/include/sbuild/sbuild-chroot-facet-union.h
/usr/include/sbuild/sbuild-chroot-facet-userdata.h
/usr/include/sbuild/sbuild-chroot-facet.h
/usr/include/sbuild/sbuild-chroot-file.h
/usr/include/sbuild/sbuild-chroot-loopback.h
/usr/include/sbuild/sbuild-chroot-lvm-snapshot.h
/usr/include/sbuild/sbuild-chroot-plain.h
/usr/include/sbuild/sbuild-chroot.h
/usr/include/sbuild/sbuild-ctty.h
/usr/include/sbuild/sbuild-custom-error.h
/usr/include/sbuild/sbuild-environment.h
/usr/include/sbuild/sbuild-error.h
/usr/include/sbuild/sbuild-error.tcc
/usr/include/sbuild/sbuild-fdstream.h
/usr/include/sbuild/sbuild-feature.h
/usr/include/sbuild/sbuild-format-detail.h
/usr/include/sbuild/sbuild-i18n.h
/usr/include/sbuild/sbuild-keyfile-base.h
/usr/include/sbuild/sbuild-keyfile.h
/usr/include/sbuild/sbuild-lock.h
/usr/include/sbuild/sbuild-log.h
/usr/include/sbuild/sbuild-mntstream.h
/usr/include/sbuild/sbuild-nostream.h
/usr/include/sbuild/sbuild-null.h
/usr/include/sbuild/sbuild-parse-error.h
/usr/include/sbuild/sbuild-parse-value.h
/usr/include/sbuild/sbuild-personality.h
/usr/include/sbuild/sbuild-regex.h
/usr/include/sbuild/sbuild-run-parts.h
/usr/include/sbuild/sbuild-session.h
/usr/include/sbuild/sbuild-tr1types.h
/usr/include/sbuild/sbuild-types.h
/usr/include/sbuild/sbuild-util.h