sieve-filter ignores -u argument

Hello I try to test my sieve script, but found out that it is impossible to use a sieve-filter tool with virtual mail users. It always uses a real user name instead of passed via -u argument.

# sieve-filter -v -u postmaster@domain.tld ~/sieve/managesieve.sieve INBOX sieve-filter(root): Fatal: Unknown user

sudo -u vmail sieve-filter -u postmaster@domain.tld ~/sieve/managesieve.sieve INBOX sieve-filter(vmail): Fatal: Unknown user

Also there is the same question on serverfault, but without an answer. https://serverfault.com/questions/1055407/how-to-make-sieve-filter-use-virtu...

My environment is Ubuntu 20.04 dovecot --version 2.3.7.2 (3c910f64b)

-- Sincerely, Andrey Kunitsyn