pub fn manifest_path(&mut self, path: impl Into<PathBuf>) -> &mut Self {
        self.inner.manifest_path(path);
        self
    }
Sets the path to `Cargo.toml`.

By default, this will look for `Cargo.toml` in the ancestors of the current directory. Note
that this doesn't need to be the root `Cargo.toml` in a workspace -- any member of the
workspace is fine.
guppy/src/metadata_command.rs