/usr/lib/locale/eu_FR/ is in locales-all 2.24-11+deb9u4.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/locale/eu_FR.utf8/LC_ADDRESS
/usr/lib/locale/eu_FR.utf8/LC_COLLATE
/usr/lib/locale/eu_FR.utf8/LC_CTYPE
/usr/lib/locale/eu_FR.utf8/LC_IDENTIFICATION
/usr/lib/locale/eu_FR.utf8/LC_MEASUREMENT
/usr/lib/locale/eu_FR.utf8/LC_MESSAGES/
/usr/lib/locale/eu_FR.utf8/LC_MESSAGES/SYS_LC_MESSAGES
/usr/lib/locale/eu_FR.utf8/LC_MONETARY
/usr/lib/locale/eu_FR.utf8/LC_NAME
/usr/lib/locale/eu_FR.utf8/LC_NUMERIC
/usr/lib/locale/eu_FR.utf8/LC_PAPER
/usr/lib/locale/eu_FR.utf8/LC_TELEPHONE
/usr/lib/locale/eu_FR.utf8/LC_TIME
/usr/lib/locale/eu_FR/LC_ADDRESS
/usr/lib/locale/eu_FR/LC_COLLATE
/usr/lib/locale/eu_FR/LC_CTYPE
/usr/lib/locale/eu_FR/LC_IDENTIFICATION
/usr/lib/locale/eu_FR/LC_MEASUREMENT
/usr/lib/locale/eu_FR/LC_MESSAGES/
/usr/lib/locale/eu_FR/LC_MESSAGES/SYS_LC_MESSAGES
/usr/lib/locale/eu_FR/LC_MONETARY
/usr/lib/locale/eu_FR/LC_NAME
/usr/lib/locale/eu_FR/LC_NUMERIC
/usr/lib/locale/eu_FR/LC_PAPER
/usr/lib/locale/eu_FR/LC_TELEPHONE
/usr/lib/locale/eu_FR/LC_TIME
/usr/lib/locale/eu_FR@euro/LC_ADDRESS
/usr/lib/locale/eu_FR@euro/LC_COLLATE
/usr/lib/locale/eu_FR@euro/LC_CTYPE
/usr/lib/locale/eu_FR@euro/LC_IDENTIFICATION
/usr/lib/locale/eu_FR@euro/LC_MEASUREMENT
/usr/lib/locale/eu_FR@euro/LC_MESSAGES/
/usr/lib/locale/eu_FR@euro/LC_MESSAGES/SYS_LC_MESSAGES
/usr/lib/locale/eu_FR@euro/LC_MONETARY
/usr/lib/locale/eu_FR@euro/LC_NAME
/usr/lib/locale/eu_FR@euro/LC_NUMERIC
/usr/lib/locale/eu_FR@euro/LC_PAPER
/usr/lib/locale/eu_FR@euro/LC_TELEPHONE
/usr/lib/locale/eu_FR@euro/LC_TIME