According tohttps://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-PARAMKEYWORDS

If the host name starts with @, it is taken as a Unix-domain socket in the abstract namespace (currently supported on Linux and Windows).

However tokio-posgresconnect preventshost=@... ; the error is

calledResult::unwrap() on anErr value: Custom { kind: Uncategorized, error: "failed to lookup address information: Name or service not known" }

And the backtrace points to this linehttps://github.com/sfackler/rust-postgres/blob/02463b1/tokio-postgres/src/connect.rs#L98