What are you doing?

Assume $DATABASE_URL points to a real Postgres database.

const Sequelize = require('sequelize');

function main() {
  const sequelize = new Sequelize(
    process.env.DATABASE_URL,
    {dialect: 'postgres', operatorsAliases: false}
  );

  return sequelize.query(`select 1`);
}

main();

Full environment details and demo available at https://github.com/Vadskye/demo-sequelize.

What do you expect to happen?

The script should finish its execution 10 seconds after the query finishes, when the connection times out and all active connections have been closed. This was the behavior with Sequelize v3.

What is actually happening?

The script hangs indefinitely after the query finishes.

Dialect: postgres
Dialect version: 6.4.2
Database version: 9.4
Sequelize version: 4.13.8
Tested with master branch: No; there is one commit to master since the last release, and it does not affect this issue.