Files to reproduce databinding error in 3.1.0-alpha06

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <data>

        <variable
            name="login"
            type="com.test.android.login.viewmodels.LoginViewmodel" />
    </data>

    <android.support.constraint.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="?colorPrimary">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginStart="8dp"
            android:layout_marginTop="8dp"
            android:background="?attr/colorPrimary"
            android:minHeight="?attr/actionBarSize"
            android:theme="?attr/actionBarTheme"
            app:layout_constraintBottom_toTopOf="@+id/cardView"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_chainStyle="packed">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="bottom"
                android:orientation="horizontal"
                android:paddingEnd="5dp">


                <ImageView
                    android:id="@+id/img_college_logo"
                    android:layout_width="85dp"
                    android:layout_height="85dp"
                    android:layout_gravity="bottom|center_vertical"

                    android:src="@mipmap/ic_launcher" />

                <TextView
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_gravity="center_vertical"
                    android:layout_marginStart="12dp"
                    android:text="Welcome!"
                    android:textAppearance="@style/TextAppearance.Widget.AppCompat.Toolbar.Title" />


            </LinearLayout>
        </android.support.v7.widget.Toolbar>

        <android.support.v7.widget.CardView
            android:id="@+id/cardView"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginStart="8dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/toolbar">

            <android.support.constraint.ConstraintLayout
                android:id="@+id/formParent"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:animateLayoutChanges="true">

                <android.support.design.widget.TextInputLayout
                    android:id="@+id/txtInputEmail"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="8dp"
                    app:error="@{login.userNameError}"
                    app:errorEnabled="true"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toTopOf="parent">

                    <android.support.design.widget.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:hint="Email"
                        android:inputType="textEmailAddress"
                        android:text="@={login.userName}" />

                    <requestFocus />
                </android.support.design.widget.TextInputLayout>

                <android.support.design.widget.TextInputLayout
                    android:id="@+id/txtInputPassword"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    app:error="@{login.passwordError}"
                    app:errorEnabled="true"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toBottomOf="@+id/txtInputEmail"
                    app:passwordToggleEnabled="true">

                    <android.support.design.widget.TextInputEditText
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:hint="Password"
                        android:inputType="textPassword"
                        android:maxLines="1"
                        android:text="@={login.password}" />
                </android.support.design.widget.TextInputLayout>

                <Button
                    android:id="@+id/btnSignIn"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:layout_marginEnd="0dp"
                    android:layout_marginStart="0dp"
                    android:text="Sign In"
                    android:textColor="@android:color/white"
                    app:layout_constraintBottom_toBottomOf="parent"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toBottomOf="@+id/txtInputPassword" />

                <ProgressBar
                    android:id="@+id/progressBar"
                    style="?android:attr/progressBarStyle"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:layout_marginEnd="0dp"
                    android:layout_marginStart="0dp"
                    android:visibility="gone"
                    app:layout_constraintBottom_toBottomOf="parent"
                    app:layout_constraintEnd_toEndOf="parent"
                    app:layout_constraintStart_toStartOf="parent"
                    app:layout_constraintTop_toBottomOf="@+id/txtInputPassword" />
            </android.support.constraint.ConstraintLayout>
        </android.support.v7.widget.CardView>
    </android.support.constraint.ConstraintLayout>
</layout>

LoginActivity.kt

class LoginActivity : AppCompatActivity() {


	@Inject lateinit var loginPresenter: LoginPresenter

	lateinit var binding: ActivityLoginBinding

	val loginViewModel: LoginViewmodel by lazy {
		LoginViewmodel()
	}

	override fun onCreate(savedInstanceState: Bundle?) {
		AndroidInjection.inject(this)
		super.onCreate(savedInstanceState)
		binding = DataBindingUtil.setContentView(this, R.layout.activity_login)
		
		binding.login = loginViewModel

		btnSignIn.setOnClickListener {
			if (loginViewModel.isValid) {
				loginPresenter.doLogin(loginViewModel.loginModel)
			}
		}

		observe(loginPresenter.loginResponse) {
			when (it) {
				is Loading                    -> showLoading()
				is SuccessData<LoginResponse> -> handleData(it.data)
				is WebserviceError            -> handleError(it.throwable)

			}
		}
	}

	private fun handleError(throwable: Throwable) {
		hideLoading()
	}

	private fun handleData(data: LoginResponse?) {
		hideLoading()
		d("Login resp: $data")

	}

	private fun showLoading() {
		btnSignIn.setVisible(false)
		progressBar.setVisible(true)
	}

	private fun hideLoading() {
		btnSignIn.setVisible(true)
		progressBar.setVisible(false)
	}
}

LoginViewModel.kt

class LoginViewmodel : BaseObservable() {
	var userName: String = ""
		@Bindable get

	var password: String = ""
		@Bindable get

	var userNameError: String = ""
		@Bindable get

	var passwordError: String = ""
		@Bindable get

	val isValid: Boolean
		get() {
			userNameError = ""
			notifyPropertyChanged(BR.userNameError)
			passwordError = ""
			notifyPropertyChanged(BR.passwordError)
			return when {
				userName.isEmptyString() -> {
					userNameError = "Please enter username"
					notifyPropertyChanged(BR.userNameError)
					false
				}
				password.isEmptyString() -> {
					passwordError = "Please enter password"
					notifyPropertyChanged(BR.passwordError)
					false
				}
				else                     -> true
			}

		}

	val loginModel: LoginRequest
		get() = LoginRequest(userName = userName, password = password)
}