#44439 adds meta.tests to dovecot, but that attribute is not supported by Nix and causes evaluation errors, i.e.:

$ nix-env -qaP --meta --json  >/dev/null
derivation 'dovecot-2.3.3' has invalid meta attribute 'tests'
derivation 'opensmtpd-6.4.0p1' has invalid meta attribute 'tests'

This output breaks several scripts of mine (for updating the Haskell package set) and I would kindly request to make those warnings disappear one way or another.

Ping: @Ekleog, @timokau