Hot Reload vs. Edit and Continue: Choosing a Debug Iteration Strategy for .NET 8 Apps

Context

Visual Studio 2022 offers two mechanisms for applying code changes during a debug session without restarting: Hot Reload (introduced in 2022) and the legacy Edit and Continue (EnC). Hot Reload applies edits while the process continues running, supporting a wider range of changes such as adding methods, modifying lambdas, and updating Razor components. Edit and Continue requires the debugger to be paused at a breakpoint and does not support asynchronous methods, generic type modifications, or iterator blocks.

Constraint

The primary constraint is minimizing developer iteration time for a .NET 8 application that includes both backend services and a Blazor Server front end. Hot Reload is faster for UI-heavy flows because it never forces a pause, but it can fail silently for unsupported edits—particularly those involving generic type parameters or async state machines—leaving the running code unchanged without a clear error in the Output window.

Uncertainty

When Hot Reload encounters an unsupported edit, Visual Studio may silently fall back to Edit and Continue if the debugger is already paused. The exact conditions that trigger this fallback are not fully documented and appear to vary by .NET runtime version. This makes it difficult to predict whether a given edit will be applied seamlessly, require a manual pause, or demand a full restart.

Questions

1. What documented criteria determine whether Visual Studio falls back to Edit and Continue versus prompting for a restart when Hot Reload encounters an unsupported edit in .NET 8?
2. Is there a reliable way to detect silent Hot Reload failures (e.g., generic method signature changes) during a debug session without relying on the Output window?
3. For a mixed Blazor Server / API solution, does the fallback behavior differ between the server-side C# hot reload path and the Razor component hot reload path?