dovecot and with it came a tool called
maildirlock that I would like to use. It's not in PATH, but it is in /nix/store. Multiple times in different versions, of course (and they can be found with
find /nix/store/ -iname "maildirlock").
How do I identify the version matching the currently installed (and running) dovecot? What is the idiomatic way for doing so? Is there a tool for this?