Adapt minimally to the possible absence of a repo

Of the API methods, ListControllers is the only one for which a git
repo is optional; make it return a response with less information,
rather than an error, if the repo is not ready.

Some other methods either don't try to look at the repo (ListImages), in
which case no change is needed.

The remainder refer to the repo (usually because they want to write to
it), so must return an error. That will happen as things stand, since
attempting to clone the repo results in an error.

daemon/daemon.go

@@ -79,7 +79,10 @@ func (d *Daemon) ListServices(ctx context.Context, namespace string) ([]flux.Con
 		services, err = d.Manifests.ServicesWithPolicies(checkout.ManifestDir())
 		return err
 	})
-	if err != nil {
+	switch {
+	case err == git.ErrNotReady:
+		services = policy.ResourceMap{}
+	case err != nil:
 		return nil, errors.Wrap(err, "getting service policies")
 	}
 

git/working.go

@@ -45,7 +45,7 @@ func (r *Repo) Clone(ctx context.Context, conf Config) (*Checkout, error) {
 	upstream := r.Origin()
 	repoDir, err := r.workingClone(ctx, conf.Branch)
 	if err != nil {
-		return nil, CloningError(upstream.URL, err)
+		return nil, err
 	}
 
 	if err := config(ctx, repoDir, conf.UserName, conf.UserEmail); err != nil {