Work-around Root Volume unmounting

resources/arguments.py

@@ -1,6 +1,8 @@
 import sys
 from resources import defaults, build, utilities, validation, sys_patch, sys_patch_auto
 from data import model_array
+import threading
+import time
 
 # Generic building args
 class arguments:
@@ -101,7 +103,16 @@ If you plan to create the USB for another machine, please select the "Change Mod
                 print("- Set Mojave/Catalina root patch configuration")
                 settings.moj_cat_accel = True
             print("- Set System Volume patching")
-            sys_patch.PatchSysVolume(settings.custom_model or settings.computer.real_model, settings, None).start_patch()
+
+            if "Library/InstallerSandboxes/" in str(self.constants.payload_path):
+                print("- Running from Installer Sandbox")
+                thread = threading.Thread(target=sys_patch.PatchSysVolume(settings.custom_model or settings.computer.real_model, settings, None).start_patch)
+                thread.start()            
+                while thread.is_alive():
+                    utilities.block_os_updaters()
+                    time.sleep(1)
+            else:
+                sys_patch.PatchSysVolume(settings.custom_model or settings.computer.real_model, settings, None).start_patch()
         elif self.args.unpatch_sys_vol:
             print("- Set System Volume unpatching")
             sys_patch.PatchSysVolume(settings.custom_model or settings.computer.real_model, settings, None).start_unpatch()

resources/sys_patch.py

@@ -241,9 +241,13 @@ class PatchSysVolume:
         else:
             result = utilities.elevated(["kextcache", "-i", f"{self.mount_location}/"], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
 
-        # kextcache always returns 0, even if it fails
-        # Check the output for 'KernelCache ID' to see if the cache was successfully rebuilt
-        if result.returncode != 0 or (self.constants.detected_os < os_data.os_data.catalina and "KernelCache ID" not in result.stdout.decode()):
+        # kextcache notes:
+        # - kextcache always returns 0, even if it fails
+        # - Check the output for 'KernelCache ID' to see if the cache was successfully rebuilt
+        # kmutil notes:
+        # - kmutil will return 71 on failure to build KCs
+        # - kmutil will sometimes have a stroke and return a negative value even if it succeeds
+        if result.returncode > 0 or (self.constants.detected_os < os_data.os_data.catalina and "KernelCache ID" not in result.stdout.decode()):
             self.success_status = False
             print("- Unable to build new kernel cache")
             print(f"\nReason for Patch Failure({result.returncode}):")
@@ -254,7 +258,7 @@ class PatchSysVolume:
                 input("Press [ENTER] to continue")
         else:
             self.success_status = True
-            print("- Successfully built new kernel cache")
+            print(f"- Successfully built new kernel cache({result.returncode})")
             if self.root_supports_snapshot is True:
                 print("- Creating new APFS snapshot")
                 bless = utilities.elevated(

resources/utilities.py

@@ -410,6 +410,29 @@ def monitor_disk_output(disk):
     output = output[-2]
     return output
 
+
+def block_os_updaters():
+    # Disables any processes that would be likely to mess with 
+    # the root volume while we're working with it.
+    bad_processes = [
+        "softwareupdate",
+        "SoftwareUpdate",
+        "Software Update",
+        "MobileSoftwareUpdate",
+    ]
+    output = subprocess.check_output(["ps", "-ax"])
+    lines = output.splitlines()
+    for line in lines:
+        entry = line.split() 
+        pid = entry[0]
+        process_name = entry[3].decode()
+        for process in bad_processes:
+            if process in process_name:
+                if pid != "":
+                    print(f"Killing PID: {pid}")
+                    print(f"Process: {process_name}")
+                    subprocess.run(["kill", "-9", pid])
+
 def check_boot_mode():
     # Check whether we're in Safe Mode or not
     sys_plist = plistlib.loads(subprocess.run(["system_profiler", "SPSoftwareDataType"], stdout=subprocess.PIPE).stdout)