Azure Pipeline Failing in dotnet build, need to upgrade to latest .net core version

Question

I'm having an issue with my deployment in my Azure Pipeline for my.Net Core API deployment.

The build is failing because recently the API was upgraded from.Net Core 3.1 to.Net Core 5.0.

How do I upgrade the version in the deployed API?

The build is failing because of it.

    2020-12-15T17:28:36.4659829Z Welcome to .NET Core 3.1!
2020-12-15T17:28:36.4663885Z ---------------------
2020-12-15T17:28:36.4664170Z SDK Version: 3.1.404
2020-12-15T17:28:36.4664326Z 
2020-12-15T17:28:36.4664473Z Telemetry
2020-12-15T17:28:36.4664777Z ---------
2020-12-15T17:28:36.4665979Z The .NET Core tools collect usage data in order to help us improve your experience. It is collected by Microsoft and shared with the community. You can opt-out of telemetry by setting the DOTNET_CLI_TELEMETRY_OPTOUT environment variable to '1' or 'true' using your favorite shell.
2020-12-15T17:28:36.4666549Z 
2020-12-15T17:28:36.4667054Z Read more about .NET Core CLI Tools telemetry: https://aka.ms/dotnet-cli-telemetry
2020-12-15T17:28:36.4667516Z 
2020-12-15T17:28:36.4667822Z ----------------
2020-12-15T17:28:36.4668277Z Explore documentation: https://aka.ms/dotnet-docs
2020-12-15T17:28:36.4668662Z Report issues and find source on GitHub: https://github.com/dotnet/core
2020-12-15T17:28:36.4669205Z Find out what's new: https://aka.ms/dotnet-whats-new
2020-12-15T17:28:36.4669786Z Learn about the installed HTTPS developer cert: https://aka.ms/aspnet-core-https
2020-12-15T17:28:36.4673694Z Use 'dotnet --help' to see available commands or visit: https://aka.ms/dotnet-cli-docs
2020-12-15T17:28:36.4678355Z Write your first app: https://aka.ms/first-net-core-app
2020-12-15T17:28:36.4678944Z --------------------------------------------------------------------------------------
2020-12-15T17:28:36.7880706Z Microsoft (R) Build Engine version 16.7.1+52cd83677 for .NET
2020-12-15T17:28:36.7881990Z Copyright (C) Microsoft Corporation. All rights reserved.
2020-12-15T17:28:36.7882687Z 
2020-12-15T17:28:37.4462789Z   Determining projects to restore...
2020-12-15T17:28:44.3820962Z   Restored /home/vsts/work/1/s/SynApi/SynApi.csproj (in 6.57 sec).
2020-12-15T17:28:45.1453408Z /home/vsts/work/1/s/Api/Api.csproj : warning NU1604: Project dependency Microsoft.AspNetCore.App does not contain an inclusive lower bound. Include a lower bound in the dependency version to ensure consistent restore results. [/home/vsts/work/1/s/Api.sln]

2020-12-15T17:28:45.5916387Z   Failed to restore /home/vsts/work/1/s/SynApi/SynApi.csproj (in 7.85 sec).
2020-12-15T17:28:45.6085564Z 
2020-12-15T17:28:45.6087169Z Build FAILED.

Answer 1

Azure doesn't come with.Net 5 just yet. Insert a new step at the beginning of your pipeline to install.Net 5:

  - task: UseDotNet@2
    displayName: .Net 5
    inputs:
      version: 5.0.100

Or, if you are using the classic graphical interface, add the step Use.NetCore and make sure you use the right version. As of today it is 5.0.100.