Having issues with hot reloading and locked DLLs

Describe the bug I can’t seem to get hot reloading to work. The plugin DLLs are locked by dotnet.exe even with EnableHotReload = true.

The hot-reload sample in this repository yielded the same results.

Using .NET Core SDK v3.1.100 on Windows.

To Reproduce Steps to reproduce the behavior:

1. Install .NET Core SDK v3.1.100 on Windows
2. Clone this (DotNetCorePlugins) repository
3. Run /samples/hot-reload/run.sh
4. Output:

run.sh: Use CTRL+C to exit
TimestampedPlugin: this plugin was compiled at 9:05:24 a.m.
run.sh: Rebuilding plugin...

C:\Program Files\dotnet\sdk\3.1.100\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Publish.targets(155,5): warning MSB3026: Could not copy "C:\Source\DotNetCorePlugins\.build\obj\TimestampedPlugin\Debug\netstandard2.0\TimestampedPlugin.dll" to "C:\Source\DotNetCorePlugins\samples\hot-reload\bin\plugins\TimestampedPlugin\TimestampedPlugin.dll". Beginning retry 1 in 1000ms. The process cannot access the file 'C:\Source\DotNetCorePlugins\samples\hot-reload\bin\plugins\TimestampedPlugin\TimestampedPlugin.dll' because it is being used by another process.

Expected behavior The plugin DLL is successfully overwritten and the PluginLoader gets reloaded.

[Andale-online]

I’m on Win10 / VS2019 - does that fit? Think I’m gonna try the sample later. We will see…

[Andale-online]

This may occur in many circumstances. Even an open explorer.exe pointing to that directory may have a lock on files. I think there are some tools like sysinternals process explorer, which can show you who’s locking the file.