Hello

debian-security-support 1:14+2026.05.07 fails to install (al less using debstrap/chroot) because the /var/lib/debian-security-support/ directory does not exist. 

Setting up debian-security-support (1:14+2026.05.07) ...
/usr/bin/check-support-status: 282: cannot create /var/lib/debian-security-support/security-support.semaphore: Directory nonexistent
dpkg: error processing package debian-security-support (--configure):
 old debian-security-support package postinst maintainer script subprocess failed with exit status 2
Errors were encountered while processing:
 debian-security-support

The expected "mkdir" does not exist in the package "posinst"
USERNAME=debian-security-support
LIB_DIR="/var/lib/$USERNAME"
[...]
case "$1" in
configure)
[...]
        runuser --user="$USERNAME" -- \
            check-support-status \
                --type "$MODE" \
                --no-heading \
                --status-db "$LIB_DIR/security-support.semaphore" \
            >"$OUTPUT"

The error was introduced by deleting the adduser support (which included 
        mkdir "$LIB_DIR"
        chown $USERNAME:$USERNAME "$LIB_DIR"
in the stanza) by introducing systemd-sysusers.

From a "keep it simple" approach (and init-agnostic approach too), the best is to recover adduser stanza. However, it is possible to leave the new systemd-sysusers and add the missing "mkdir" and "chown" lines in package "posinst".

Thanks.