IssueTracker

Android Studio version:
Android Studio 3.2 Beta 1
Build #AI-181.4892.42.32.4847800, built on June 19, 2018
JRE: 1.8.0_152-release-1136-b04 amd64
JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 10 10.0
Libraries used:
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'androidx.appcompat:appcompat:1.0.0-alpha3'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test:runner:1.1.0-alpha3'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0-alpha3'
    implementation 'com.google.android.material:material:1.0.0-alpha3'

Steps:

Create a new project.
Edit the layout XML file.
Replace all with a layout file of a different project. The layout could include various resources that don't exist on the new project, and usage of classes that don't exist there.

The bug:
It doesn't mark anything with red underline, as if everything is ok.
Not only that, but it fails to auto-complete anything.

Here's an example of a layout file that should have a lot of errors on such a case:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar" android:layout_width="match_parent" android:layout_height="?attr/actionBarSize"
        android:theme="@style/AppTheme.WhiteAppBarOverlay"/>

    <android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent" android:layout_height="wrap_content" android:fillViewport="true"
        android:overScrollMode="never">

        <LinearLayout
            android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical">

            <android.support.v7.widget.AppCompatImageView
                android:id="@+id/button" style="@style/SecondaryButton" android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="@dimen/some_dimen"
                android:src="@drawable/some_drawable"/>

        </LinearLayout>
    </android.support.v4.widget.NestedScrollView>
</LinearLayout>

In the above example, we have :
- resources that don't exist, of various types
- classes that don't exist (example: NestedScrollView on this path)
- no auto-completion, even on framwork classes
- no red underline for anything
- even after a build everything in the XML is not marked.

Attached sample video showing the issue.