stash changes (still buggy)

engine/Scripts/lib_build.py

 flutter_root_path=""
 visual_studio_path=""
 architecture=""
+gclientSyncCmd=""
 
 def get_opts():
     # get intput agrs
 def set_env_verb():
     global platform
     global flutter_root_path
-    flutter_root_path = os.getenv('FLUTTER_ROOT_PATH', 'null')
-    if flutter_root_path == 'null':
-        os.environ["FLUTTER_ROOT_PATH"] = os.path.join(engine_path, "engine","src")
-        flutter_root_path = os.getenv('FLUTTER_ROOT_PATH')
-    else:
-        print("This environment variable has been set, skip")
-    env_path = os.getenv('PATH')
-    path_strings = re.split("[;:]", env_path)
-    for path in path_strings:
-        if path.endswith("depot_tools"):
-            print("This environment variable has been set, skip")
-            return
-    if platform == "windows":
-        os.environ["PATH"] = engine_path + "/depot_tools;" + os.environ["PATH"]
+    #if the user provides us an valid engine path, use it
+    if not engine_path == "":
+        flutter_root_path = os.path.join(engine_path, "engine","src")
+    #if the engine path is not set, we try to fetch it from the environment variables
-        os.environ["PATH"] = engine_path + "/depot_tools:" + os.environ["PATH"]
+        flutter_root_path = os.getenv('FLUTTER_ROOT_PATH', 'null')
+        if flutter_root_path == 'null':
+            assert False, "flutter root path is invalid. Please use -r to specify a root path for the third party flutter repos"
+    global gclientSyncCmd
+
     print("\nGetting Depot Tools...")
     if not os.path.exists(engine_path):
         assert False,"Flutter engine path is not exist, please set the path by using \"-r\" param to set a engine path."
         os.chdir(engine_path)
         os.system("git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git")
-        os.system("gclient sync")
+    
+    # we use the absolute path to execute gthe client command
+    gclientSyncCmd = engine_path + "depot_tools/gclient sync"
 
 def get_flutter_engine():
     global engine_path
     f.write(content)
     f.close()
     os.chdir(Path(engine_path + "/engine"))
-    os.system("gclient sync")
+    os.system(gclientSyncCmd)
+    if not os.path.exists(Path(flutter_root_path + "/flutter")):
+        os.makedirs(Path(flutter_root_path + "/flutter"))
+    
-    os.system("gclient sync -D")
+    os.system(gclientSyncCmd + " -D")
 
 def compile_engine():
     global flutter_root_path
         f = open(Path(flutter_root_path + "/out/" + output_path + "/args.gn"), 'a')
         f.write("icu_use_data_file = false")
         f.close()
+        #the contents in the include path below may conflict with those in MacSDK 12.0, so we'd better remove them as a work-around
+        os.system("rm -rf " + flutter_root_path + "/buildtools/mac-x64/clang/include")
         os.system("ninja " + ninja_params)
     elif platform == "ios":
         old_str = "bitcode_marker = true"

engine/Scripts/patches/find_sdk.patch

    else:
      sdk_dir = os.path.join(out.rstrip(), 'SDKs')
 -  sdks = [re.findall('^MacOSX(10\.\d+)\.sdk$', s) for s in os.listdir(sdk_dir)]
-+  sdks = [re.findall('^MacOSX(1[0-1]\.\d+)\.sdk$', s) for s in os.listdir(sdk_dir)]
++  sdks = [re.findall('^MacOSX(1[0-2]\.\d+)\.sdk$', s) for s in os.listdir(sdk_dir)]
    sdks = [s[0] for s in sdks if s]  # [['10.5'], ['10.6']] => ['10.5', '10.6']
    sdks = [s for s in sdks  # ['10.5', '10.6'] => ['10.6']
            if parse_version(s) >= parse_version(min_sdk_version)]