#dotnet-build

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 fresh git worktree of an s&box project cannot dotnet build, because the editor generates Code/<project>.csproj and gitignores it, and the csproj references the Steam engine DLLs by relative paths tied to the main tree's directory depth. A naive copy fails with MSB3245 when the worktree nests one level deeper. The durable fix rewrites the csproj with absolute engine paths and redirects OutputPath into an isolated folder. That second half matters everywhere: the default OutputPath is the shared .vs/output/ folder with no project segment, so any CLI build on the machine writes into the same directory. A sibling build there empties a running editor's TypeLibrary, and every game component reads as MissingComponent while compile_status still reports Success. Build headless with the editor closed and output redirected, or pass -p:OutputPath to keep the build out of the shared directory.

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.