https://github.com/scriban/scriban/blame/3f49de5085311625aa9d1f9bc5577b9da3ff62fd/src/Scriban/Helpers/NullableCompatibility.cs#L90

I'm using Scriban as part a source generator project, to help with compatibility of code I had my own version of the line I referenced above:

namespace System.Runtime.CompilerServices { [EditorBrowsable(EditorBrowsableState.Never)] internal static class IsExternalInit { } }

Upgrading Scriban to version 7.0.4 caused a duplicate declaration compile error, I commented out my one and it works again. Just raising this as an FYI.

I'm unsure how you would do this, but your declaration should be wrapped in some way to either prevent the conflict or perhaps have a way to turn it off.