$ ./pre-inst-env guix refresh -l rsync
Building the following 39 packages would ensure 124 dependent packages
are rebuilt ...

This patchset also fixes the casync build.

The only dependency failing to build is ocaml-craml, for which the
only release was in 2018 and has had no commits since other than the
addition of a deprecation notice with a given alternative of mdx,
which is available in guix as ocaml-mdx. No other packages depend on
ocaml-craml. Should this package be removed?

Greg