title: Flutter upgrade error: Your local changes to the following files would be overwritten
body: <p>Upgrading the Flutter SDK and packages     </p>
  
  <pre><code>    My-Mac:~ admin$ flutter upgrade
  
      Upgrading Flutter from /Users/admin/Desktop/SDK/flutter...
      error: Your local changes to the following files would be overwritten by merge:
          packages/flutter/lib/src/services/message_codecs.dart
      Please commit your changes or stash them before you merge.
      Aborting
      Updating 2eeeXXXe9..7XXXbf4aX
  </code></pre>
  
  <p>I have gone on the flutter SDK and check <code>status</code> and got below things</p>
  
  <pre><code>My-Mac:flutter admin$  git status
  On branch master
  Your branch is behind 'origin/master' by 565 commits, and can be fast-forwarded.
    (use "git pull" to update your local branch)
  
  Changes not staged for commit:
    (use "git add &lt;file&gt;..." to update what will be committed)
    (use "git checkout -- &lt;file&gt;..." to discard changes in working directory)
  modified:   dev/automated_tests/pubspec.yaml
  modified:   dev/benchmarks/complex_layout/pubspec.yaml
  modified:   dev/benchmarks/macrobenchmarks/pubspec.yaml
  modified:   dev/benchmarks/microbenchmarks/pubspec.yaml
  modified:   dev/bots/pubspec.yaml
  modified:   dev/devicelab/pubspec.yaml
  modified:   dev/integration_tests/android_semantics_testing/pubspec.yaml
  modified:   dev/integration_tests/android_views/pubspec.yaml
  modified:   dev/integration_tests/channels/pubspec.yaml
  modified:   dev/integration_tests/external_ui/pubspec.yaml
  modified:   dev/integration_tests/flavors/pubspec.yaml
  modified:   dev/integration_tests/platform_interaction/pubspec.yaml
  modified:   dev/integration_tests/ui/pubspec.yaml
  modified:   dev/manual_tests/pubspec.yaml
  modified:   dev/snippets/pubspec.yaml
  modified:   dev/tools/pubspec.yaml
  modified:   dev/tools/vitool/pubspec.yaml
  modified:   examples/catalog/pubspec.yaml
  modified:   examples/flutter_gallery/pubspec.yaml
  modified:   examples/hello_world/pubspec.yaml
  modified:   examples/layers/pubspec.yaml
  modified:   examples/platform_channel/pubspec.yaml
  modified:   examples/platform_channel_swift/pubspec.yaml
  modified:   examples/stocks/pubspec.yaml
  modified:   packages/flutter/lib/src/services/message_codecs.dart
  modified:   packages/flutter/pubspec.yaml
  modified:   packages/flutter_driver/pubspec.yaml
  modified:   packages/flutter_goldens/pubspec.yaml
  modified:   packages/flutter_localizations/pubspec.yaml
  modified:   packages/flutter_test/pubspec.yaml
  modified:   packages/flutter_tools/pubspec.yaml
  modified:   packages/fuchsia_remote_debug_protocol/pubspec.yaml
  
  Untracked files:
    (use "git add &lt;file&gt;..." to include in what will be committed)
  
      OLDSDK.zip
  
  no changes added to commit (use "git add" and/or "git commit -a")
  </code></pre>
  
  <p>After do above task now try to upgrade again Flutter but got again error mentioned below</p>
  
  <pre><code>My-Mac:flutter admin$ flutter upgrade
      Building flutter tool...
      Because flutter_tools depends on sockjs_client 0.3.5 which doesn't match any versions, version solving failed.
      Error: Unable to 'pub upgrade' flutter tool. Retrying in five seconds... (9 tries left)
      .
      .
      Error: Unable to 'pub upgrade' flutter tool. Retrying in five seconds... (1 tries left)
      Command 'pub upgrade' still failed after 10 tries, giving up.
  </code></pre>