I am also able to reproduce a crash using the provided code; however, it does not immediately crash for me; rather, if I select the text then it will crash (with a metal-related error). I'm running MacOS Sequoia (15.5) with XCode Version 26.0 beta 4 (17A5285i).

I see a very similar issue. The swift code has a text editor (NSTextView) and as soon as a scroll bar is added, the app crashes with an error like: [MTLDebugRenderCommandEncoder setRenderPipelineState:]:1616: failed assertion `Set Render Pipeline State Validation For color attachment 0, the texture sample count (1) does not match the renderPipelineState sampleCount (1065353216). and a similar-looking stacktrace involving MTLReportFailureand other drawing-related functions like QuartzCore (draw_shape, array_flush, draw_elements, draw etc). Possibly relevant - this is on an older intel mac with a now-unsupported GPU.