Bookshelf js fetchAll withRelated option returns empty relation object - attempt to reproduce

package.json

{
  "name": "bookshelf-relations",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "bookshelf": "^0.9.1",
    "knex": "^0.9.0",
    "sqlite3": "^3.1.1"
  }
}

session.out

➜  bookshelf-relations rm data.sqlite3 
rm: remove regular file ‘data.sqlite3’? y
➜  bookshelf-relations node
> var knex = require('knex')({client:'sqlite3',connection:{filename: 'data.sqlite3'}});
undefined
> var bookshelf = require('bookshelf')(knex);
undefined
> var up = function(knex, Promise) {
...     return knex.schema.createTable("backfire", function(table) {
.....         table.increments("id").primary();
.....         table.string("response").notNullable();
.....         table.string("created_by").notNullable();
.....         table.timestamps();
.....     }).then(function(){
.....         return knex.schema.createTable("backfireTrigger", function(table) {
.......             table.increments("id").primary();
.......             table.string("trigger").notNullable();
.......             table.integer("backfire_id").unsigned().notNullable().references("id").inTable("backfire");
.......             table.string("created_by").notNullable();
.......             table.timestamps();
.......         });
.....     });
... };
undefined
> up(knex);
Promise {
  _bitField: 0,
  _fulfillmentHandler0: undefined,
  _rejectionHandler0: undefined,
  _progressHandler0: undefined,
  _promise0: undefined,
  _receiver0: undefined,
  _settledValue: undefined }
> var Backfire = bookshelf.Model.extend({
...     tableName: 'backfire',
...     backfireTriggers: function() {
.....         return this.hasMany(BackfireTrigger);
.....     }
... });
undefined
> 
> var BackfireTrigger = bookshelf.Model.extend({
...     tableName: 'backfireTrigger',
...     backfire: function() {
.....         return this.belongsTo(Backfire);
.....     }
... });
undefined
> var bf1, bf2;
undefined
> new Backfire({response: 'twist', created_by: 'twister'}).
...     save().
...     then(function(bf) {
...         bf1 = bf.id;
...         return new Backfire({response: 'shout', created_by: 'shouter'}).
...             save();
...     }).
...     then(function(bf) {
...         bf2 = bf.id;
...         return new BackfireTrigger({trigger: 'death', backfire_id: bf1, created_by: 'dead'}).
...             save();
...     }).
...     then(function() {
...         return new BackfireTrigger({trigger: 'birth', backfire_id: bf2, created_by: 'mother'}).
...             save();
...     }).
...     then(function() {
...         return new BackfireTrigger({trigger: 'fall', backfire_id: bf2, created_by: 'faller'}).
...             save();
...     }).
...     then(function() {
...         return new BackfireTrigger({trigger: 'attack', backfire_id: bf2, created_by: 'attacker'}).
...             save();
...     }).
...     then(function() {
...         return BackfireTrigger.
...             fetchAll({withRelated: ['backfire']}).
...             then(function(result) {
.....                 console.log(result.toJSON());
.....             });
...     });
Promise {
  _bitField: 131072,
  _fulfillmentHandler0: undefined,
  _rejectionHandler0: undefined,
  _progressHandler0: undefined,
  _promise0: undefined,
  _receiver0: undefined,
  _settledValue: undefined,
  _boundTo: 
   ModelBase {
     attributes: { response: 'twist', created_by: 'twister' },
     _previousAttributes: {},
     changed: { response: 'twist', created_by: 'twister' },
     relations: {},
     cid: 'c1' } }
> [ { id: 1,
    trigger: 'death',
    backfire_id: 1,
    created_by: 'dead',
    created_at: null,
    updated_at: null,
    backfire: 
     { id: 1,
       response: 'twist',
       created_by: 'twister',
       created_at: null,
       updated_at: null } },
  { id: 2,
    trigger: 'birth',
    backfire_id: 2,
    created_by: 'mother',
    created_at: null,
    updated_at: null,
    backfire: 
     { id: 2,
       response: 'shout',
       created_by: 'shouter',
       created_at: null,
       updated_at: null } },
  { id: 3,
    trigger: 'fall',
    backfire_id: 2,
    created_by: 'faller',
    created_at: null,
    updated_at: null,
    backfire: 
     { id: 2,
       response: 'shout',
       created_by: 'shouter',
       created_at: null,
       updated_at: null } },
  { id: 4,
    trigger: 'attack',
    backfire_id: 2,
    created_by: 'attacker',
    created_at: null,
    updated_at: null,
    backfire: 
     { id: 2,
       response: 'shout',
       created_by: 'shouter',
       created_at: null,
       updated_at: null } } ]

source.js

var knex = require('knex')({client:'sqlite3',connection:{filename: 'data.sqlite3'}});
var bookshelf = require('bookshelf')(knex);
var up = function(knex, Promise) {
    return knex.schema.createTable("backfire", function(table) {
        table.increments("id").primary();
        table.string("response").notNullable();
        table.string("created_by").notNullable();
        table.timestamps();
    }).then(function(){
        return knex.schema.createTable("backfireTrigger", function(table) {
            table.increments("id").primary();
            table.string("trigger").notNullable();
            table.integer("backfire_id").unsigned().notNullable().references("id").inTable("backfire");
            table.string("created_by").notNullable();
            table.timestamps();
        });
    });
};

up(knex);

var Backfire = bookshelf.Model.extend({
    tableName: 'backfire',
    backfireTriggers: function() {
        return this.hasMany(BackfireTrigger);
    }
});

var BackfireTrigger = bookshelf.Model.extend({
    tableName: 'backfireTrigger',
    backfire: function() {
        return this.belongsTo(Backfire);
    }
});

var bf1, bf2;
new Backfire({response: 'twist', created_by: 'twister'}).
    save().
    then(function(bf) {
        bf1 = bf.id;
        return new Backfire({response: 'shout', created_by: 'shouter'}).
            save();
    }).
    then(function(bf) {
        bf2 = bf.id;
        return new BackfireTrigger({trigger: 'death', backfire_id: bf1, created_by: 'dead'}).
            save();
    }).
    then(function() {
        return new BackfireTrigger({trigger: 'birth', backfire_id: bf2, created_by: 'mother'}).
            save();
    }).
    then(function() {
        return new BackfireTrigger({trigger: 'fall', backfire_id: bf2, created_by: 'faller'}).
            save();
    }).
    then(function() {
        return new BackfireTrigger({trigger: 'attack', backfire_id: bf2, created_by: 'attacker'}).
            save();
    }).
    then(function() {
        return BackfireTrigger.
            fetchAll({withRelated: ['backfire']}).
            then(function(result) {
                console.log(result.toJSON());
            });
    });