iOS forward: invoke pymobiledevice3 as a module, fail early when absent

First MacBook-run finding, as the UNVERIFIED marker predicted: a
pip-installed console script not being on PATH is the normal state on
macOS, and because the forward runs as a background Popen, the bare
FileNotFoundError only surfaced later as an unreachable port. The
forward now runs as [sys.executable, -m, pymobiledevice3, ...]
(verified working by the iOS session) and prepare() checks the module
imports first, exiting with an actionable message instead.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: Staacks

tools/lab/device.py

@@ -11,6 +11,7 @@
 """
 
 import subprocess
+import sys
 import time
 import urllib.parse
 import urllib.request
@@ -122,11 +123,19 @@ def __init__(self, udid, port):
     def prepare(self, fixture_port=None):
         self.fixture_port = fixture_port
         # forward local port -> device port 80 (the app's server on
-        # hardware). pymobiledevice3 is the portable choice; iproxy works
-        # too. UNVERIFIED on hardware.
+        # hardware). Invoked as a MODULE: a pip-installed console script
+        # not being on PATH is the normal state on macOS, and a missing
+        # binary in a background Popen would only surface later as an
+        # unreachable port (found on the first MacBook run, 2026-08-26).
+        try:
+            import pymobiledevice3  # noqa: F401 - presence check only
+        except ImportError:
+            raise SystemExit(
+                "pymobiledevice3 is not installed for this Python "
+                f"({sys.executable}) - pip install pymobiledevice3")
         self._forward = subprocess.Popen(
-            ["pymobiledevice3", "usbmux", "forward", str(self.port), "80",
-             "--serial", self.udid],
+            [sys.executable, "-m", "pymobiledevice3", "usbmux", "forward",
+             str(self.port), "80", "--serial", self.udid],
             stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
         time.sleep(1)
 

tools/lab/devices/iphone-14-pro.skeleton.yml

@@ -0,0 +1,9 @@
+device: iphone-14-pro
+recorded: hand-finish this file into devices/iphone-14-pro.yml - see README
+experiments:
+  accelerometer.phyphox: launch failed
+  gyroscope.phyphox: launch failed
+  magnetometer.phyphox: launch failed
+  pressure.phyphox: launch failed
+  light.phyphox: launch failed
+  gps.phyphox: launch failed

tools/lab/lab.yml

@@ -5,13 +5,13 @@
 
 hosts:
   macbook:            # the default full set
-    host_ip: 192.168.2.50     # how iOS devices reach this host's fixture server
+    host_ip: 192.168.2.195    # how iOS devices reach this host's fixture server
     aapt: aapt                # or the full path into Android build-tools
     artifacts:                # optional: enables the languages release check
       android: /home/dicon/phyphox/git/phyphox-android/app/regular/release/phyphox-release.apk
       ios: /path/to/phyphox.ipa
     devices:
-      iphone-14-pro: {platform: ios, serial: "UDID-HERE", port: 8081}
+      iphone-14-pro: {platform: ios, serial: "00008120-001C31520EC0C01E", port: 8081}
       iphone-8:      {platform: ios, serial: "UDID-HERE", port: 8082}
       ipad-pro:      {platform: ios, serial: "UDID-HERE", port: 8083}
       pixel-9-pro:   {platform: android, serial: "53291FDAP0026B", port: 8091}