Why is dotnet watch (with hot reloading) not working?

Question

Dotnet watch / hot reload doesn't seem to work at all. Any ideas? Or am I just doing something wrong?

Program.cs:

while(true)
{
    Thread.Sleep(1000);
    Console.WriteLine("a");
}

Then on the command line:

dotnet watch
dotnet watch  Hot reload enabled. For a list of supported edits, see https://aka.ms/dotnet/hot-reload.
   Press "Ctrl + R" to restart.
dotnet watch  Building...
  Determining projects to restore...
  Restored xxx.csproj (in 91 ms).
  test -> xxx/bin/Debug/net7.0/xxx.dll
dotnet watch  Started
a
a
a
(etc)

As expected. Then change "a" to "b" in the above and get this output:

dotnet watch ⌚ File changed: ./Program.cs.
a
dotnet watch  Hot reload of changes succeeded.
a
a
a
(etc)

Notice it's still outputting "a" not "b".

I'm running macOS and from the standard command line. The csproj file looks like this:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net7.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
</Project>

TIA.

Answer 1

Extract the changed code into a separate function:

while(true)
{
    Thread.Sleep(1000);
    F();
}

void F()
{
    Console.WriteLine("b");
}

As stated in the docs:

The following changes can't be applied to C# and Visual Basic code during a debugging session:

• Changes to the current statement or any other active statement.
  Active statements include any statements, in functions on the call stack, that were called to get to the current statement.