Programable API catch error Error: [object Object]

[WClouds]

When I use db-migrate programable API, I meet the follow error:

{ Error: [object Object]
    at /Users/zhaiyafei/saas/tx-model-server/node_modules/db-migrate/lib/commands/on-complete.js:12:9
    at tryCatcher (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/util.js:16:23)
    at Promise.successAdapter [as _fulfillmentHandler0] (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/nodeify.js:22:30)
    at Promise._settlePromise (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/promise.js:566:21)
    at Promise._settlePromise0 (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/promise.js:614:10)
    at Promise._settlePromises (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/promise.js:693:18)
    at Async._drainQueue (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/async.js:133:16)
    at Async._drainQueues (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/async.js:143:10)
    at Immediate.Async.drainQueues (/Users/zhaiyafei/saas/tx-model-server/node_modules/bluebird/js/release/async.js:17:14)
    at runCallback (timers.js:789:20)
    at tryOnImmediate (timers.js:751:5)
    at processImmediate [as _immediateCallback] (timers.js:722:5)

My code is:

const dbmigrate = DBMigrate.getInstance(true, { config });
  dbmigrate.up()
  .then((info) => {
    console.log('after up====>', info);
  })
  .catch(err => {
    console.log('catch error===>', err);
  });

I found that the error is from on-complete.js:

migrator.driver.close(function (err) {
    if ((err || originalErr) && typeof callback === 'function') {
      callback(
        new Error({
          err: err,
          originalErr: originalErr
        })
      );
      return;
    } else {
      assert.ifError(originalErr);
      assert.ifError(err);
      log.info('Done');
    }

My question is: why callback an Error with an object? And when I catch the error, how can I parse the error to see the exact error?

[wzrdtales]

Recently when adding new CS to the project and fullfilling the requirements of this CS, explicitly error objects have been used, which was not the case before. This will need some adjustment, as the error is effectively lost here. Will take a look at it and fix the bug.