title: How to resolve "Exception: Gradle task assembleDebug failed with exit code 1"?
body: <p>Flutter Version: <em>2.6.0-12.0.pre.381</em></p>
  <p>Dart Version: <em>2.15.0</em></p>
  <p>Gradle version : <em>distributionUrl=https://services.gradle.org/distributions/gradle-6.7-all.zip</em></p>
  <p>In pubspec.yaml, I have these packages:</p>
  <pre><code>environment:
    sdk: &quot;&gt;=2.12.0 &lt;3.0.0&quot;
  
  dependencies:
    flutter:
      sdk: flutter
    # The following adds the Cupertino Icons font to your application.
    # Use with the CupertinoIcons class for iOS style icons.
    splashscreen: ^1.2.0
    bottom_navy_bar:
    cupertino_icons: ^1.0.2
    image_picker: ^0.8.0+4
    fluttertoast: ^8.0.7
    shared_preferences: ^2.0.6
    share: ^2.0.4
    flutter_barcode_scanner: ^2.0.0-nullsafety.0
    dropdown_search: ^1.0.0
    syncfusion_flutter_pdfviewer:
    ndialog: ^4.1.0
    flutter_pdfview: ^1.0.4
    http: ^0.13.3
    dio: ^4.0.0
    path_provider: ^2.0.3
    downloads_path_provider_28: ^0.1.2
    permission_handler: ^8.1.4+2
    open_file: ^3.2.1
    flutter_local_notifications: ^9.0.0
  </code></pre>
  <p>Same packages are working in another project.
  Any suggestions on how to fix the problem. I think it is due to some error in build.graddle.</p>
  <p>I have changed minSdkVersion and targetSdkVersion in build.gradle as follows:</p>
  <pre><code>        minSdkVersion 23
          targetSdkVersion 29
          multiDexEnabled true       
  </code></pre>
  <p>It is showing error while running the project:</p>
  <pre><code>Launching lib\main.dart on SM M205F in debug mode...
  Running Gradle task 'assembleDebug'...
  Note: C:\flutter\.pub-cache\hosted\pub.dartlang.org\downloads_path_provider_28-0.1.2\android\src\main\java\it\nplace\downloadspathprovider\DownloadsPathProviderPlugin.java uses or overrides a deprecated API.
  Note: Recompile with -Xlint:deprecation for details.
  Note: Some input files use or override a deprecated API.
  Note: Recompile with -Xlint:deprecation for details.
  Note: Some input files use unchecked or unsafe operations.
  Note: Recompile with -Xlint:unchecked for details.
  Note: C:\flutter\.pub-cache\hosted\pub.dartlang.org\image_picker-0.8.4+2\android\src\main\java\io\flutter\plugins\imagepicker\ImagePickerDelegate.java uses unchecked or unsafe operations.
  Note: Recompile with -Xlint:unchecked for details.
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:58: error: cannot find symbol
              if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.R) {
                                                              ^
    symbol:   variable R
    location: class VERSION_CODES
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:59: error: cannot find symbol
                  status = Environment.isExternalStorageManager()
                                      ^
    symbol:   method isExternalStorageManager()
    location: class Environment
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:254: error: cannot find symbol
                      if (permission == PermissionConstants.PERMISSION_GROUP_MANAGE_EXTERNAL_STORAGE &amp;&amp; Build.VERSION.SDK_INT &lt; Build.VERSION_CODES.R) {
                                                                                            ^
    symbol:   variable R
    location: class VERSION_CODES
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:268: error: cannot find symbol
              } else if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.R &amp;&amp; permission == PermissionConstants.PERMISSION_GROUP_MANAGE_EXTERNAL_STORAGE) {
                                                                     ^
    symbol:   variable R
    location: class VERSION_CODES
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:270: error: cannot find symbol
                          Settings.ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION,
                                  ^
    symbol:   variable ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION
    location: class Settings
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:321: error: cannot find symbol
              if (Build.VERSION.SDK_INT &lt; Build.VERSION_CODES.S) {
                                                             ^
    symbol:   variable S
    location: class VERSION_CODES
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:349: error: cannot find symbol
                  if (Build.VERSION.SDK_INT &lt; Build.VERSION_CODES.R) {
                                                                 ^
    symbol:   variable R
    location: class VERSION_CODES
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:380: error: cannot find symbol
                      if (Build.VERSION.SDK_INT &lt; Build.VERSION_CODES.R) {
                                                                     ^
    symbol:   variable R
    location: class VERSION_CODES
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionManager.java:384: error: cannot find symbol
                      return Environment.isExternalStorageManager()
                                        ^
    symbol:   method isExternalStorageManager()
    location: class Environment
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:64: error: cannot find symbol
              case Manifest.permission.MANAGE_EXTERNAL_STORAGE:
                                      ^
    symbol:   variable MANAGE_EXTERNAL_STORAGE
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:72: error: cannot find symbol
              case Manifest.permission.BLUETOOTH_SCAN:
                                      ^
    symbol:   variable BLUETOOTH_SCAN
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:74: error: cannot find symbol
              case Manifest.permission.BLUETOOTH_ADVERTISE:
                                      ^
    symbol:   variable BLUETOOTH_ADVERTISE
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:76: error: cannot find symbol
              case Manifest.permission.BLUETOOTH_CONNECT:
                                      ^
    symbol:   variable BLUETOOTH_CONNECT
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:235: error: cannot find symbol
                  if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.R &amp;&amp; hasPermissionInManifest(context, permissionNames, Manifest.permission.MANAGE_EXTERNAL_STORAGE ))
                                                                  ^
    symbol:   variable R
    location: class VERSION_CODES
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:235: error: cannot find symbol
                  if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.R &amp;&amp; hasPermissionInManifest(context, permissionNames, Manifest.permission.MANAGE_EXTERNAL_STORAGE ))
                                                                                            ^
    symbol:   variable MANAGE_EXTERNAL_STORAGE
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:236: error: cannot find symbol
                      permissionNames.add(Manifest.permission.MANAGE_EXTERNAL_STORAGE);
                                                             ^
    symbol:   variable MANAGE_EXTERNAL_STORAGE
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:259: error: cannot find symbol
                  String result = determineBluetoothPermission(context, Manifest.permission.BLUETOOTH_SCAN);
                                                                                           ^
    symbol:   variable BLUETOOTH_SCAN
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:270: error: cannot find symbol
                  String result = determineBluetoothPermission(context, Manifest.permission.BLUETOOTH_ADVERTISE);
                                                                                           ^
    symbol:   variable BLUETOOTH_ADVERTISE
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:281: error: cannot find symbol
                  String result = determineBluetoothPermission(context, Manifest.permission.BLUETOOTH_CONNECT);
                                                                                           ^
    symbol:   variable BLUETOOTH_CONNECT
    location: class permission
  C:\flutter\.pub-cache\hosted\pub.dartlang.org\permission_handler-8.2.5\android\src\main\java\com\baseflow\permissionhandler\PermissionUtils.java:370: error: cannot find symbol
          if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.S &amp;&amp; hasPermissionInManifest(context, null, permission )) {
                                                          ^
    symbol:   variable S
    location: class VERSION_CODES
  20 errors
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':permission_handler:compileDebugJavaWithJavac'.
  &gt; Compilation failed; see the compiler error output for details.
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
  
  * Get more help at https://help.gradle.org
  
  BUILD FAILED in 44s
  Exception: Gradle task assembleDebug failed with exit code 1
  </code></pre>