incorrect query marshalling the nil []string to null

[thetruechar]

create table settings
(
    aspects      jsonb       default '[]'::jsonb,
);

var a []string
Db.Query( &ss, `select * from settings where aspects @> coalesce(?, '[]'::jsonb)`, a)

the query msg will become:

select * from settings where aspects @> coalesce('null', '[]'::jsonb)

not what I expect:

select * from settings where aspects @> coalesce(null, '[]'::jsonb)

only the literal nil work:

var a []string
Db.Query( &ss, `select * from settings where aspects @> coalesce(?, '[]'::jsonb)`, nil)

results:

select * from settings where aspects @> coalesce(null, '[]'::jsonb)