Bookshelf bug - belongsToMany and fetchAll

package.json

{
	"name": "bookshelf-bug",
	"version": "0.1.0",
	"dependencies": {
		"bookshelf": "*",
		"bluebird": "*",
		"knex": "*",
		"sqlite3": "*"
	}
}

test.js

var Promise = require('bluebird')
var knex = require('knex')({
	client: 'sqlite3',
	connection: {filename: ':memory:'},
	debug: true
})
var bookshelf = require('bookshelf')(knex)
var Color = bookshelf.Model.extend({tableName: 'colors'})
var Thing = bookshelf.Model.extend({
	tableName: 'things',
	colors: function() {
		return this.belongsToMany(Color, 'thing_colors')
	}
})

Promise.all([
    knex.schema.createTable('colors', function(table) {
        table.increments()
        table.text('name').notNullable()
    }),
    knex.schema.createTable('things', function(table) {
        table.increments()
        table.text('name').notNullable()
    }),
    knex.schema.createTable('thing_colors', function(table) {
        table.increments()
        table.integer('thing_id').notNullable().references('things.id')
        table.integer('color_id').notNullable().references('colors.id')
    })
]).then(function() {
	return [
		knex('things').insert({name: 'Noemie'}),
		knex('colors').insert({name: '02 Blanc'}),
		knex('colors').insert({name: '03 Rose'}),
		knex('colors').insert({name: '01 Noir'})
	]
}).spread(function () {
	// Bad path

	return Promise.all([
		Thing.fetchAll({withRelated: ['colors']}),
		Color.forge({id: 1}).fetch()
	])


	// Good path
/*
	return Promise.all([
		Thing.forge({id: 1}).fetch(),
		Color.fetchAll()
	])
*/
}).then(function(models) {
	// Bad path
	return models[0].at(0).related('colors').attach(models[1])

	// Good path
	//return models[0].related('colors').attach(models[1].at(0))
}).then(function() {
	console.log('all done')
}).catch(function (err) {
	console.log(err)
	console.log(err.stack)
}).finally(function() {
	process.exit()
})