Postgres CopyFromQuery::from_insertable producing an error with larger structs

[emnijac]

I'm trying to copy data from a struct with more than 12 fields but I am getting a build error when creating the CopyFromQuery.

The following code produces an error when the 13th field is present but when it's commented it out, the code compiles.

#[derive(Default, Insertable)]
#[diesel(treat_none_as_default_value = false)]
#[diesel(table_name = schema::foo)]
struct Foo {
    pub bar1: i32,
    pub bar2: i32,
    pub bar3: i32,
    pub bar4: i32,
    pub bar5: i32,
    pub bar6: i32,
    pub bar7: i32,
    pub bar8: i32,
    pub bar9: i32,
    pub bar10: i32,
    pub bar11: i32,
    pub bar12: i32,
    pub bar13: i32,
}

fn main() {
    let copy_query = diesel::copy_from(schema::foo::table).from_insertable(vec![Foo::default()]);
}

I would assume that with the default 32-column-table feature enabled, I would be able to insert a struct with as many as 32 fields. Is this 12 field limit expected behavior?

[weiznich]

Thanks for reporting. This limit is not expected behavior. I've filled #4486 to fix that.