Friedrich von Never

Hm, this is interesting. Probably we have a race condition here, I'll check. Thanks!

Also, we're supposed to show an error message for such cases (and I can see that a corresponding exception, `AvaloniaPreviewerInitializationException`, has been thrown), but there's only endless progress bar spinning....

A log improvement has been merged into IntelliJ 2021.3, which will help with further investigation.

I was able to reproduce a similar exception while opening another project in the same window as I had an Avalonia Previewer opened.

Try implementing `IBreakpointVariantsProvider` on the backend.

While this is expected, we have to handle it somehow (e.g. offer the user a button to build the project, the same as Windows Forms previewer does).

@andrfgs, for better manageability, please create a new issue about that. It is unrelated to the current one.

If so, then we should get a stable repro and report to Avalonia.

@wdcossey, this looks awesome. Have you seriously already implemented it? This is unbelievable!

@wdcossey, this is awesome. Do you want me to start PR from your branch myself? I could do that.