title: Flutter: pub get failed
body: <p>Flutter project showing me a warning <code>'Packages get' has not been run</code> with suggested solutions,</p>
  <ul>
  <li>Get Dependencies</li>
  <li>Upgrade Dependencies</li>
  <li>Ignore</li>
  </ul>
  <p>As suggested by <a href="https://stackoverflow.com/users/8394265/darky">Darky</a>, in this <a href="https://stackoverflow.com/a/49056175/5638630">answer</a> to go ahead with 'Get Dependencies'</p>
  <p>I tried it but it shows me an error:</p>
  <blockquote>
  <p><strong>pub get failed</strong></p>
  </blockquote>
  <pre><code>/SoftSources/Flutter/flutter/bin/flutter --no-color packages get
  Running &quot;flutter packages get&quot; in catalog...
  Incompatible version constraints on test:
  - flutter_test 0.0.0 depends on version 0.12.30+3
  - sample_catalog depends on version 0.12.30+4
  pub get failed (1)
  Process finished with exit code 1
  </code></pre>
  <p>An error indicates an issue with the version of the project (or something else), where should change it in my flutter project?</p>
  <p><strong>Edit:</strong> <em>pubspec.yaml</em></p>
  <pre><code>name: sample_catalog
  description: A collection of Flutter sample apps
  dependencies:
    flutter:
      sdk: flutter
    path: 1.5.1
  
  dev_dependencies:
    flutter_test:
      sdk: flutter
    flutter_driver:
      sdk: flutter
  
    args: 1.3.0 # TRANSITIVE DEPENDENCY
    async: 2.0.4 # TRANSITIVE DEPENDENCY
    barback: 0.15.2+14 # TRANSITIVE DEPENDENCY
    boolean_selector: 1.0.2 # TRANSITIVE DEPENDENCY
    charcode: 1.1.1 # TRANSITIVE DEPENDENCY
    cli_util: 0.1.2+1 # TRANSITIVE DEPENDENCY
    collection: 1.14.5 # TRANSITIVE DEPENDENCY
    convert: 2.0.1 # TRANSITIVE DEPENDENCY
    crypto: 2.0.2+1 # TRANSITIVE DEPENDENCY
    csslib: 0.14.1 # TRANSITIVE DEPENDENCY
    file: 2.3.6 # TRANSITIVE DEPENDENCY
    glob: 1.1.5 # TRANSITIVE DEPENDENCY
    html: 0.13.2+2 # TRANSITIVE DEPENDENCY
    http: 0.11.3+16 # TRANSITIVE DEPENDENCY
    http_multi_server: 2.0.4 # TRANSITIVE DEPENDENCY
    http_parser: 3.1.1 # TRANSITIVE DEPENDENCY
    intl: 0.15.2 # TRANSITIVE DEPENDENCY
    io: 0.3.2+1 # TRANSITIVE DEPENDENCY
    isolate: 1.1.0 # TRANSITIVE DEPENDENCY
    js: 0.6.1 # TRANSITIVE DEPENDENCY
    json_rpc_2: 2.0.7 # TRANSITIVE DEPENDENCY
    logging: 0.11.3+1 # TRANSITIVE DEPENDENCY
    matcher: 0.12.1+4 # TRANSITIVE DEPENDENCY
    meta: 1.1.2 # TRANSITIVE DEPENDENCY
    mime: 0.9.6 # TRANSITIVE DEPENDENCY
    mockito: 2.2.3 # TRANSITIVE DEPENDENCY
    multi_server_socket: 1.0.1 # TRANSITIVE DEPENDENCY
    node_preamble: 1.4.0 # TRANSITIVE DEPENDENCY
    package_config: 1.0.3 # TRANSITIVE DEPENDENCY
    package_resolver: 1.0.2 # TRANSITIVE DEPENDENCY
    plugin: 0.2.0+2 # TRANSITIVE DEPENDENCY
    pool: 1.3.4 # TRANSITIVE DEPENDENCY
    pub_semver: 1.3.2 # TRANSITIVE DEPENDENCY
    quiver: 0.28.0 # TRANSITIVE DEPENDENCY
    shelf: 0.7.2 # TRANSITIVE DEPENDENCY
    shelf_packages_handler: 1.0.3 # TRANSITIVE DEPENDENCY
    shelf_static: 0.2.7 # TRANSITIVE DEPENDENCY
    shelf_web_socket: 0.2.2 # TRANSITIVE DEPENDENCY
    source_map_stack_trace: 1.1.4 # TRANSITIVE DEPENDENCY
    source_maps: 0.10.4 # TRANSITIVE DEPENDENCY
    source_span: 1.4.0 # TRANSITIVE DEPENDENCY
    stack_trace: 1.9.1 # TRANSITIVE DEPENDENCY
    stream_channel: 1.6.3 # TRANSITIVE DEPENDENCY
    string_scanner: 1.0.2 # TRANSITIVE DEPENDENCY
    term_glyph: 1.0.0 # TRANSITIVE DEPENDENCY
    test: 0.12.30+4 # TRANSITIVE DEPENDENCY
    typed_data: 1.1.5 # TRANSITIVE DEPENDENCY
    utf: 0.9.0+4 # TRANSITIVE DEPENDENCY
    vector_math: 2.0.5 # TRANSITIVE DEPENDENCY
    vm_service_client: 0.2.4+1 # TRANSITIVE DEPENDENCY
    watcher: 0.9.7+7 # TRANSITIVE DEPENDENCY
    web_socket_channel: 1.0.7 # TRANSITIVE DEPENDENCY
    yaml: 2.1.13 # TRANSITIVE DEPENDENCY
  
  flutter:
    uses-material-design: true
  </code></pre>