/usr/include/regina-normal/utilities/ is in regina-normal-dev 5.1-2build1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/regina-normal/utilities/base64.h
/usr/include/regina-normal/utilities/bitmanip.h
/usr/include/regina-normal/utilities/bitmask.h
/usr/include/regina-normal/utilities/boolset.h
/usr/include/regina-normal/utilities/flags.h
/usr/include/regina-normal/utilities/i18nutils.h
/usr/include/regina-normal/utilities/intutils.h
/usr/include/regina-normal/utilities/listoncall.h
/usr/include/regina-normal/utilities/markedvector.h
/usr/include/regina-normal/utilities/memutils.h
/usr/include/regina-normal/utilities/nbooleans.h
/usr/include/regina-normal/utilities/osutils.h
/usr/include/regina-normal/utilities/property.h
/usr/include/regina-normal/utilities/ptrutils.h
/usr/include/regina-normal/utilities/qitmask.h
/usr/include/regina-normal/utilities/registryutils.h
/usr/include/regina-normal/utilities/safepointeebase.h
/usr/include/regina-normal/utilities/safeptr.h
/usr/include/regina-normal/utilities/saferemnant.h
/usr/include/regina-normal/utilities/sequence.h
/usr/include/regina-normal/utilities/stringutils-impl.h
/usr/include/regina-normal/utilities/stringutils.h
/usr/include/regina-normal/utilities/trieset.h
/usr/include/regina-normal/utilities/tritmask.h
/usr/include/regina-normal/utilities/xmlcallback.h
/usr/include/regina-normal/utilities/xmlelementreader.h
/usr/include/regina-normal/utilities/xmlutils.h