[√] Flutter (Channel master, v1.12.6-pre.15, on Microsoft Windows [Version 10.0.18363.476], locale en-GB)
    • Flutter version 1.12.6-pre.15 at C:\Android\flutter
    • Framework revision 43a8a1902e (5 hours ago), 2019-11-21 12:09:43 +0100
    • Engine revision 7a77e3625d
    • Dart version 2.7.0
 


[√] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
    • Android SDK at C:\Android\
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-28, build-tools 28.0.3
    • ANDROID_HOME = C:\Android
    • ANDROID_SDK_ROOT = C:\Android\sdk
    • Java binary at: C:\Android\openjdk\bin\java
    • Java version OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_202-b08)
    • All Android licenses accepted.

[!] Android Studio (not installed)
    • Android Studio not found; download from https://developer.android.com/studio/index.html
      (or visit https://flutter.dev/setup/#android-setup for detailed instructions).

[√] VS Code (version 1.40.1)
    • VS Code at C:\Users\tvalois\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.6.0

[√] Connected device (1 available)
    • Android SDK built for x86 • emulator-5554 • android-x86 • Android 9 (API 28) (emulator)

The plugin "cloud_firestore" is built using an older version of the Android plugin API which assumes that it's running in a full-Flutter environment. It may have undefined behaviors when Flutter is integrated into an existing app as a module.
The plugin can be updated to the v2 Android Plugin APIs by following 
https://flutter.dev/go/android-plugin-migration.
Launching lib\main.dart on Android SDK built for x86 in debug mode...

Note: C:\Android\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.12.10+2\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: C:\Android\flutter\.pub-cache\hosted\pub.dartlang.org\cloud_firestore-0.12.10+2\android\src\main\java\io\flutter\plugins\firebase\cloudfirestore\CloudFirestorePlugin.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
Note: C:\Android\flutter\.pub-cache\hosted\pub.dartlang.org\firebase_analytics-5.0.6\android\src\main\java\io\flutter\plugins\firebaseanalytics\FirebaseAnalyticsPlugin.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: C:\Android\flutter\.pub-cache\hosted\pub.dartlang.org\firebase_core-0.4.1+5\android\src\main\java\io\flutter\plugins\firebase\core\FirebaseCorePlugin.java uses or overrides a deprecated API.

Gradle build failed to produce an .apk file. It's likely that this file was generated under C:\Users\...\build, but the tool couldn't find it.