pub fn query_workspace_paths(
        &self,
        paths: impl IntoIterator<Item = impl AsRef<Utf8Path>>,
    ) -> Result<PackageQuery, Error> {
        let workspace = self.workspace();
        let package_ixs = paths
            .into_iter()
            .map(|path| {
                workspace
                    .member_by_path(path.as_ref())
                    .map(|package| package.package_ix())
            })
            .collect::<Result<SortedSet<_>, Error>>()?;

        Ok(self.query_from_parts(package_ixs, DependencyDirection::Forward))
    }
Creates a new forward query over the specified workspace packages by path.

Returns an error if any workspace paths were unknown.
guppy/src/graph/query.rs