概要

using System.Linq;
using UnityEditor;
using UnityEditor.Compilation;

[InitializeOnLoad]
internal static class Example
{
    static Example()
    {
        CompilationPipeline.assemblyCompilationFinished -= OnFinished;
        CompilationPipeline.assemblyCompilationFinished += OnFinished;

        static void OnFinished
        (
            string            assemblyName,
            CompilerMessage[] messages
        )
        {
            if ( messages.All( x => x.type != CompilerMessageType.Error ) ) return;

            EditorApplication.Beep();
        }
    }
}