title: Building .NET Core 2.1 app fails in Google Cloud Shell
body: <p>I've created an ASP.NET Core <strong>2.1</strong> app that I'm trying to deploy to <em>Google Cloud Platform</em>. It builds just fine using <code>dotnet build</code> locally.</p>
  
  <p>I cannot build it through Google Cloud Shell, though. Running <code>dotnet --version</code> confirms the Google Cloud Shell has .NET Core <em>2.0</em> installed.</p>
  
  <p>Running <code>gcloud app deploy</code> initiates a deployment of the app, but I receive a cryptic error from the log saying:</p>
  
  <blockquote>
    <p>Step #0: Status: Downloaded newer image for gcr.io/gcp-runtimes/aspnetcorebuild@sha256:ad1b788a9b4cca75bb61eb523ef358ca059c4bd208fba15a10ccc6acab83f49a</p>
    
    <p>Step #0: No .deps.json file found for the app
    Finished Step #0</p>
    
    <p>ERROR: build step 0 "gcr.io/gcp-runtimes/aspnetcorebuild@sha256:ad1b788a9b4cca75bb61eb523ef358ca059c4bd208fba15a10ccc6acab83f49a" failed: exit status 1</p>
  </blockquote>
  
  <p>I was under the impression that GCP supports .NET Core <strong>2.1</strong> containers by default, so I haven't included a <em>Dockerfile</em>.</p>
  
  <p>I'm trying to deploy to the <strong>flexible</strong> environment, here's my <code>app.yaml</code> file:</p>
  
  <pre><code>runtime: aspnetcore
  env: flex
  </code></pre>
  
  <p>Do I need to create a custom Docker container? Or is there some other way to get support for .NET Core 2.1 in Google Cloud Shell?</p>
  
  <p><strong>Edit:</strong> For now I've installed Google Cloud Tools to run <code>gcloud app deploy</code> in a shell locally after running <code>dotnet publish</code>.</p>