This code:

@MainActor
import SwiftUI

@MainActor
func renderImage(_ view: some View) -> CGImage? {
    let renderer = ImageRenderer(content: view)
    return renderer.cgImage
}

let image = renderImage(
    ZStack {
        Image(systemName: "drop.fill").foregroundStyle(.white)
        Image(systemName: "drop").foregroundStyle(.black)
    }.font(.system(size: 30))
)

Compiles but shows warning:

Conformance of underlying type of 'some View' to protocol 'View' may be isolated and cannot be passed to main actor-isolated context

Xcode 27.0 beta 4
Swift Concurrency Checking: Complete
Approachable Concurrency: No
Default Actor Isolation: nonisolated

If I understand correctly:
The issue seems to be that .font() returns an opaque type "some View".
And "some View" may also conform to View only constrained to some actor.
(as in "struct A: @someGlobalActor View").

But renderImage() is @MainActor, and thus the view it is passed, needs to conform to View from the main actor. renderImage() needs to be @MainActor, because ImageRenderer.init() is @MainActor.

Is there any way to fix this warning?