/usr/ is in lupin-casper 0.51.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/initramfs-tools/
/usr/share/initramfs-tools/hooks/
/usr/share/initramfs-tools/hooks/lupin_casper
/usr/share/initramfs-tools/scripts/
/usr/share/initramfs-tools/scripts/lupin-helpers
/usr/share/initramfs-tools/scripts/casper-premount/
/usr/share/initramfs-tools/scripts/casper-premount/30custom_installation
/usr/share/initramfs-tools/scripts/casper-premount/20iso_scan
/usr/share/initramfs-tools/scripts/casper-bottom/
/usr/share/initramfs-tools/scripts/casper-bottom/05mountpoints_lupin
/usr/share/initramfs-tools/scripts/casper-bottom/10custom_installation
/usr/share/initramfs-tools/scripts/casper-bottom/10ntfs_3g
/usr/share/doc/
/usr/share/doc/lupin-casper/
/usr/share/doc/lupin-casper/copyright
/usr/share/doc/lupin-casper/changelog.gz