Installing the current libargon2-1 could stop you logging in.The bug has been noted, along with workarounds.
$ LANG=C apt policy cryptsetup cryptsetup: Installed: 2:2.6.1-2 Candidate: 2:2.6.1-2 Version table: *** 2:2.6.1-2 500 500 https://deb.debian.org/debian unstable/main amd64 Packages 100 /var/lib/dpkg/status