title: Unable to build Puppeteer-Sharp on MacOS, Jan-2021
body: <p>have tried to build the <a href="https://github.com/hardkoded/puppeteer-sharp" rel="nofollow noreferrer">Puppeteer Sharp project</a> on my mac machine and failed in a somehow strange way.
  After cloning the repo, creating <a href="https://github.com/hardkoded/puppeteer-sharp/blob/master/CONTRIBUTING.md" rel="nofollow noreferrer">test server certificate</a> and installing .Net Core SDK 2.2.207.
  I tried to build the solution within the lib folder:</p>
  <p><code>dotnet build PuppeteerSharp.sln</code></p>
  <p>The build starts and fails in, AFAIK corect way</p>
  <pre><code>  Restore completed in 115.15 ms for *****/workspace/puppeteer-sharp/lib/PuppeteerSharp.Tests.DumpIO/PuppeteerSharp.Tests.DumpIO.csproj.
    Restore completed in 117.49 ms for *****/workspace/puppeteer-sharp/lib/PuppeteerSharp.DevicesFetcher/PuppeteerSharp.DevicesFetcher.csproj.
    Restore completed in 160.85 ms for *****/workspace/puppeteer-sharp/lib/PuppeteerSharp.Tests/PuppeteerSharp.Tests.csproj.
    Restore completed in 4.54 ms for *****/workspace/puppeteer-sharp/lib/PuppeteerSharp/PuppeteerSharp.csproj.
    PuppeteerSharp.TestServer -&gt; *****/workspace/puppeteer-sharp/lib/PuppeteerSharp.TestServer/bin/Debug/netcoreapp2.2/PuppeteerSharp.TestServer.dll
  FrameManager.cs(102,50): error CS0121: 
  The call is ambiguous between the following methods or properties:
  'System.Collections.Generic.CollectionExtensions.GetValueOrDefault&lt;TKey, TValue&gt;(System.Collections.Generic.IReadOnlyDictionary&lt;TKey, TValue&gt;, TKey)' and
  'PuppeteerSharp.Helpers.DictionaryExtensions.GetValueOrDefault&lt;TKey, TValue&gt;(System.Collections.Generic.IDictionary&lt;TKey, TValue&gt;, TKey)'
  [*****/workspace/puppeteer-sharp/lib/PuppeteerSharp/PuppeteerSharp.csproj]
  ...
  </code></pre>
  <p>There are several other errors with similar reasons.</p>
  <p>My question what can I do to build the project?
  The ambiguous reference is valid, the <a href="https://github.com/dotnet/runtime/blob/master/src/libraries/System.Collections/src/System/Collections/Generic/CollectionExtensions.cs" rel="nofollow noreferrer">.Net package</a> does implements the same extension method as the <a href="https://github.com/hardkoded/puppeteer-sharp/blob/master/lib/PuppeteerSharp/Helpers/DictionaryExtensions.cs" rel="nofollow noreferrer">puppeteer-sharp helper class</a> and both are referenced in the <a href="https://github.com/hardkoded/puppeteer-sharp/blob/master/lib/PuppeteerSharp/FrameManager.cs" rel="nofollow noreferrer">FrameManager.cs class</a></p>
  <p>THX Murx</p>