The behaviour was changed in commit 42ce7437ee68150ee29f5272428aa4fc657dc6dc The comments introduced here say: ``` # error if both POSTGRES_PASSWORD is unset and POSTGRES_HOST_AUTH_METHOD is not 'trust' ``` But the actual test against POSTGRES_PASSWORD is `[ -z "$POSTGRES_PASSWORD" ]` which is different from what the comment suggests. The correct test to match the comment would be: `[ ! -v POSTGRES_PASSWORD ]`. The current implementation prevents the password explicitly being set to the empty string, and issues a misleading error when it is.