CMS Airship's minimum requirements are:
We detected an older version of either libsodium or PECL libsodium. If you
were relying on your operating system's package manager for libsodium, it's
highly likely you are stuck with 1.0.3 or 1.0.8,
instead of the minimum CMS Airship needs.
CMS Airship uses the Argon2i password hashing function which was not added
to libsodium until 1.0.9; this is an absolute minimum version.
Please follow the instructions for compiling libsodium from source (and petition your package maintainer to stop providing stale versions of security-critical libraries).
You will almost certainly need to run pecl uninstall libsodium
first. Take care to compile the underlying library before running
pecl upgrade again.
CMS Airship is Free software developed by Paragon Initiative Enterprises.