/usr/share/ltsp/plugins/ltsp-build-client/Debian/ is in ltsp-server 5.5.1-1ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/ltsp/plugins/ltsp-build-client/Debian/000-basic-configuration
/usr/share/ltsp/plugins/ltsp-build-client/Debian/000-daemon-handling
/usr/share/ltsp/plugins/ltsp-build-client/Debian/001-apt-keys
/usr/share/ltsp/plugins/ltsp-build-client/Debian/001-set-accept-unsigned-packages
/usr/share/ltsp/plugins/ltsp-build-client/Debian/001-set-arch
/usr/share/ltsp/plugins/ltsp-build-client/Debian/001-set-components
/usr/share/ltsp/plugins/ltsp-build-client/Debian/001-set-dist
/usr/share/ltsp/plugins/ltsp-build-client/Debian/002-cross-arch
/usr/share/ltsp/plugins/ltsp-build-client/Debian/005-tmpdir
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-apt-pinning
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-chroot-tagging
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-debconf-frontend
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-debconf-seeds
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-debootstrap
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-distribution-specific
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-enable-popcon
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-etc-hostname
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-etc-mtab
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-http-proxy
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-manage-mirror
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-mount-proc
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-multistrap
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-nbd-client
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-pulseaudio-tweaks
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-serial-console
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-updates-mirrors
/usr/share/ltsp/plugins/ltsp-build-client/Debian/010-var-lib-nfs
/usr/share/ltsp/plugins/ltsp-build-client/Debian/013-security-mirror
/usr/share/ltsp/plugins/ltsp-build-client/Debian/015-backports
/usr/share/ltsp/plugins/ltsp-build-client/Debian/015-sources-list
/usr/share/ltsp/plugins/ltsp-build-client/Debian/020-apt-get-update
/usr/share/ltsp/plugins/ltsp-build-client/Debian/020-kernel-img-conf
/usr/share/ltsp/plugins/ltsp-build-client/Debian/020-kernel-selection
/usr/share/ltsp/plugins/ltsp-build-client/Debian/025-locales
/usr/share/ltsp/plugins/ltsp-build-client/Debian/025-var-rw-subdirs
/usr/share/ltsp/plugins/ltsp-build-client/Debian/030-default-lts-conf
/usr/share/ltsp/plugins/ltsp-build-client/Debian/030-early-packages
/usr/share/ltsp/plugins/ltsp-build-client/Debian/030-fat-client
/usr/share/ltsp/plugins/ltsp-build-client/Debian/030-late-packages
/usr/share/ltsp/plugins/ltsp-build-client/Debian/030-loopback
/usr/share/ltsp/plugins/ltsp-build-client/Debian/035-apt-get-upgrade
/usr/share/ltsp/plugins/ltsp-build-client/Debian/035-copy-timezone
/usr/share/ltsp/plugins/ltsp-build-client/Debian/035-create-fs-image
/usr/share/ltsp/plugins/ltsp-build-client/Debian/035-default-modules
/usr/share/ltsp/plugins/ltsp-build-client/Debian/035-install-debs
/usr/share/ltsp/plugins/ltsp-build-client/Debian/035-kiosk
/usr/share/ltsp/plugins/ltsp-build-client/Debian/040-copy-package-cache
/usr/share/ltsp/plugins/ltsp-build-client/Debian/040-copy-package-lists
/usr/share/ltsp/plugins/ltsp-build-client/Debian/040-mount-package-cache
/usr/share/ltsp/plugins/ltsp-build-client/Debian/080-eatmydata
/usr/share/ltsp/plugins/ltsp-build-client/Debian/090-clean-package-cache
/usr/share/ltsp/plugins/ltsp-build-client/Debian/095-exports
/usr/share/ltsp/plugins/ltsp-build-client/Debian/095-rootpass
/usr/share/ltsp/plugins/ltsp-build-client/Debian/095-squashfs-image
/usr/share/ltsp/plugins/ltsp-build-client/Debian/099-mount-cdrom
/usr/share/ltsp/plugins/ltsp-build-client/Debian/099-progress-log