error in .net8

[gmono]

1>E:\vsProjects\test2\testava\PartialMixins\PartialMixins.PartialMixin\Error_mixins.cs(2,8,2,43): error CS1029: #error: "System.ArgumentException: Inconsistent syntax tree features"
1>E:\vsProjects\test2\testava\PartialMixins\PartialMixins.PartialMixin\Error_mixins.cs(3,8,3,18): error CS1029: #error: "Parameter name: trees"
1>E:\vsProjects\test2\testava\PartialMixins\PartialMixins.PartialMixin\Error_mixins.cs(4,11,4,93): error CS1029: #error: "In Microsoft.CodeAnalysis.Compilation.SyntaxTreeCommonFeatures(IEnumerable`1 trees)"
1>E:\vsProjects\test2\testava\PartialMixins\PartialMixins.PartialMixin\Error_mixins.cs(5,11,5,184): error CS1029: #error: "In Microsoft.CodeAnalysis.CSharp.CSharpCompilation.Update(ReferenceManager referenceManager, Boolean reuseReferenceManager, SyntaxAndDeclarationManager syntaxAndDeclarations)"
1>E:\vsProjects\test2\testava\PartialMixins\PartialMixins.PartialMixin\Error_mixins.cs(6,11,6,90): error CS1029: #error: "In PartialMixins.PartialMixin.ExecuteInternal(GeneratorExecutionContext context)"
1>E:\vsProjects\test2\testava\PartialMixins\PartialMixins.PartialMixin\Error_mixins.cs(7,11,7,82): error CS1029: #error: "In PartialMixins.PartialMixin.Execute(GeneratorExecutionContext context)"
1>E:\vsProjects\test2\testava\PartialMixins\PartialMixins.PartialMixin\Error_mixins.cs(8,8,8,8): error CS1029: #error: ""