class DuckDB::PreparedStatement

def bind_hugeint(index, value)

stmt.bind_hugeint(1, 1_234_567_890_123_456_789_012_345)
stmt = PreparedStatement.new(con, sql)
sql ='SELECT name FROM users WHERE bigint_col = ?'
con = db.connect
db = DuckDB::Database.open('duckdb_database')
require 'duckdb'

This method uses bind_varchar internally.
The second argument value is to expected Integer value.
The index of first parameter is 1 not 0.
The first argument is index of parameter.
binds i-th parameter with SQL prepared statement. 
def bind_hugeint(index, value)
  case value
  when Integer
    bind_varchar(index, value.to_s)
  else
    raise(ArgumentError, "2nd argument `#{value}` must be Integer.")
  end
end