This very simple example fails in Snowflake:

CREATE OR REPLACE PROCEDURE example_procedure()
RETURNS TABLE (example_col STRING)
LANGUAGE SQL
AS
$$
DECLARE
  res resultset;
BEGIN
    WITH sample_cte AS (
        SELECT 'data' AS example_col
    )
    res := SELECT example_col FROM sample_cte;
    return table(res);
END;
$$; 

The error is confusing:

Syntax error: unexpected 'sample_cte'. (line 5)
syntax error line 5 at position 20 unexpected 'AS'. (line 5)

I’d really like to avoid building a query string and then execute immediate :query since it seems like this should work.