Hot Reload in Rider 2023.2 for .NET 6 Applications: Achieving Zero‑Downtime Migration

Resolution

Hot reload (Edit and Continue) cannot be enabled for projects targeting .NET 7 within JetBrains Rider 2023.2. There are no configuration tweaks, SDK shims, or environment variables that can force this functionality in version 2023.2, as the necessary IDE integration for the .NET 7 runtime's instrumentation was introduced in subsequent releases.

To restore hot reload capabilities for a .NET 7 migration, you must upgrade to Rider 2023.3 or later.

Technical Explanation

Hot reload in Rider is not a generic feature but a tight integration between the IDE's debugger and the specific .NET runtime's "Edit and Continue" (EnC) capabilities. Each major .NET runtime version often introduces changes to how metadata is handled or how assemblies are patched in memory. Rider 2023.2 was built to support the .NET 6 instrumentation pipeline; the internal logic required to communicate these changes to a .NET 7 process was not implemented until the 2023.3 release cycle.

Comparison and Workflow Changes

When moving from Rider 2023.2 (.NET 6) to Rider 2023.3+ (.NET 7), the core workflow remains largely the same, but with the following considerations:

• Minimal Version: Rider 2023.3 is the baseline for .NET 7 hot reload support.
• Workflow Consistency: The "Hot Reload on Save" and manual trigger mechanisms remain consistent. You still need to run the application in Debug mode for the instrumentation to attach.
• Routable Changes: As with .NET 6, structural changes (e.g., adding new methods, changing class signatures, or modifying generics) remain "non-routable" and will still prompt a full application restart.

Verification Steps

Once you have upgraded to Rider 2023.3+, verify the feature using these steps:

1. Ensure the project targets net7.0 in the .csproj file.
2. Navigate to Settings | Build, Execution, Deployment | Hot Reload and ensure the desired trigger (Automatic or Manual) is selected.
3. Launch your Minimal API in Debug mode.
4. Modify a string or a logic branch inside an existing method body and save the file.
5. Observe the Hot Reload window to confirm the change was applied without a process restart.

Diagnostic Note: If hot reload still fails after upgrading, please specify if you are using a custom launchSettings.json profile that disables the dotnet watch integration or uses a non-standard debugger attachment method.