#headless
3 items (3 fixes)
Compiling an s&box game assembly outside the editor needs the exact csproj shape the editor generates, and even a perfectly green offline build cannot surface whitelist violations. The SB1000 analyzer runs only in the editor compile pass, so code can build with 0 errors and 0 warnings offline and still be rejected in-editor. Build the editor-generated Code/<project>.csproj directly and confirm against the editor compile_status, never the offline build alone.
A headless dotnet build against the engine assemblies does not enforce the s&box sandbox access-control whitelist: code that builds clean headlessly can fail the editor compile with SB1000.
A consumer game plus a vendored library can be compile-gated fully offline using two scratch csprojs against the editor install's prebuilt base library DLL.