Change message sent to remote backend if -target used

backend/remote/backend_mock.go

@@ -760,6 +760,10 @@ func (m *mockRuns) Create(ctx context.Context, options tfe.RunCreateOptions) (*t
 		TargetAddrs:  options.TargetAddrs,
 	}
 
+	if options.Message != nil {
+		r.Message = *options.Message
+	}
+
 	if pc != nil {
 		r.PolicyChecks = []*tfe.PolicyCheck{pc}
 	}

backend/remote/backend_plan.go

@@ -209,9 +209,14 @@ in order to capture the filesystem context the remote workspace expects:
 			"Failed to upload configuration files", errors.New("operation timed out"))
 	}
 
+	queueMessage := "Queued manually using Terraform"
+	if op.Targets != nil {
+		queueMessage = "Queued manually via Terraform using -target"
+	}
+
 	runOptions := tfe.RunCreateOptions{
 		IsDestroy:            tfe.Bool(op.Destroy),
-		Message:              tfe.String("Queued manually using Terraform"),
+		Message:              tfe.String(queueMessage),
 		ConfigurationVersion: cv,
 		Workspace:            w,
 	}

backend/remote/backend_plan_test.go

@@ -301,6 +301,10 @@ func TestRemote_planWithTarget(t *testing.T) {
 		if diff := cmp.Diff([]string{"null_resource.foo"}, run.TargetAddrs); diff != "" {
 			t.Errorf("wrong TargetAddrs in the created run\n%s", diff)
 		}
+
+		if !strings.Contains(run.Message, "using -target") {
+			t.Fatalf("incorrrect Message on the created run: %s", run.Message)
+		}
 	}
 }