Function is_dirty 

pub fn is_dirty(root: &Path) -> bool

Whether the work tree has uncommitted changes to tracked files (staged or unstaged). --untracked-files=no skips the work-tree-wide untracked-file scan — the expensive, cold-cache-sensitive part of git status on a large repo (it walks to classify every path against .gitignore). This runs on every search to gate warming, so the scan dominated query-time variance.

The tradeoff: a brand-new untracked file isn’t seen as a change here, so it won’t be picked up by the opportunistic warm until it’s committed (HEAD moves → warm) or rq --indexed. Tracked edits, the common case, are still caught, and git status still refreshes the index so a touched-but-unchanged file doesn’t read as dirty. Empty stdout (clean) reports as None via git_output.