fix: add explicit dev img mounted check for dev ipsw idev cmds

cmd/ipsw/cmd/idev/idev_fsyms.go

@@ -75,6 +75,10 @@ var FetchsymsCmd = &cobra.Command{
 			ldc.Close()
 		}
 
+		if err := utils.IsDeveloperImageMounted(dev.UniqueDeviceID); err != nil {
+			return fmt.Errorf("for device %s: %w", dev.UniqueDeviceID, err)
+		}
+
 		cli, err := fetchsymbols.NewClient(dev.UniqueDeviceID)
 		if err != nil {
 			return fmt.Errorf("failed to connect to fetchsymbols service: %w", err)

cmd/ipsw/cmd/idev/idev_screen.go

@@ -88,6 +88,11 @@ var ScreenCmd = &cobra.Command{
 				return err
 			}
 			ldc.Close()
+
+			if err := utils.IsDeveloperImageMounted(dev.UniqueDeviceID); err != nil {
+				return fmt.Errorf("for device %s: ensure Developer Mode is enabled on iOS16+ AND %w", dev.UniqueDeviceID, err)
+			}
+
 			return saveScreenshot(dev, output)
 		} else {
 			devs, err := utils.PickDevices()
@@ -96,6 +101,10 @@ var ScreenCmd = &cobra.Command{
 			}
 
 			for _, dev := range devs {
+				if err := utils.IsDeveloperImageMounted(dev.UniqueDeviceID); err != nil {
+					return fmt.Errorf("for device %s: ensure Developer Mode is enabled on iOS16+ AND %w", dev.UniqueDeviceID, err)
+				}
+
 				if err := saveScreenshot(dev, output); err != nil {
 					return fmt.Errorf("failed to save screenshot: %w", err)
 				}

internal/utils/usb.go

@@ -9,6 +9,7 @@ import (
 	"github.com/apex/log"
 	"github.com/blacktop/ipsw/pkg/usb"
 	"github.com/blacktop/ipsw/pkg/usb/lockdownd"
+	"github.com/blacktop/ipsw/pkg/usb/mount"
 )
 
 func PickDevice() (*lockdownd.DeviceValues, error) {
@@ -131,3 +132,22 @@ func PickDevices() ([]*lockdownd.DeviceValues, error) {
 		return picked, nil
 	}
 }
+
+func IsDeveloperImageMounted(udid string) error {
+	cli, err := mount.NewClient(udid)
+	if err != nil {
+		return fmt.Errorf("failed to connect to mobile_image_mounter: %w", err)
+	}
+	defer cli.Close()
+
+	images, err := cli.ListImages(mount.ImageTypeDeveloper)
+	if err != nil {
+		return fmt.Errorf("failed to list images: %w", err)
+	}
+
+	if len(images) == 0 {
+		return fmt.Errorf("mount the Developer image with the `ipsw idev img mount` command or by opening Xcode")
+	}
+
+	return nil
+}

pkg/usb/fetchsymbols/fetchsymbols.go

@@ -30,7 +30,7 @@ type Client struct {
 func NewClient(udid string) (*Client, error) {
 	c, err := lockdownd.NewClientForService(serviceName, udid, false)
 	if err != nil {
-		return nil, fmt.Errorf("you might need to enable Developer Mode in your device Settings app OR mount the Developer image with `ipsw idev img mount`: %v", err)
+		return nil, fmt.Errorf("you might need to enable Developer Mode in your device Settings app: %v", err)
 	}
 	return &Client{
 		c: c,