Rider Stopped Building .NET Azure Functions Project on MacOS

The Problem

JetBrains Rider recently stopped building my .NET Core Azure Functions project on MacOS. After trying various solutions, I found one that worked for me. I'm sharing this in hopes of saving you some time if you encounter a similar issue.

Symptoms

The main issue was that Rider wouldn't build the entire solution and would only attempt to build one of the projects within it. Specifically:

• I could still build using the CLI commands dotnet build and dotnet clean.
• Rider would only build the unit test project in a solution containing:
  • A Blazor project
  • A library project
  • A unit test project
  • An Azure Functions project

I would just get the output:

Build with surface heuristics started at 09:35:00
Build completed in 00:00:00.007

Attempted Solutions

Before finding the fix, I tried several common troubleshooting steps:

1. Deleting the .idea folder in the solution root
2. Clearing Rider's caches
3. Adjusting the .NET Core SDK location in Rider settings
4. Reinstalling .NET SDKs
5. Reinstalling Azure Toolkit for Rider

The Solution

The fix that worked for me was disabling the "Use ReSharper Build" setting. Here's how to do it:

1. Go to Rider's settings
2. Navigate to Build, Execution, Deployment > Toolset and Build
3. Uncheck the "Use ReSharper Build" option

Note: This setting is disabled by default, I'm not sure why I had it so.

Conclusion

After disabling the "Use ReSharper Build" setting, Rider was able to build the entire solution again, allowing me to resume my work. If you're facing similar issues with Rider not building your .NET projects, especially Azure Functions, give this solution a try.