allow setting optional url for packages via envvar. (#5839)

* allow setting optional url for packages via envvar.

* clean up left over

* simplify code as suggested by Bernard (thanks)

* fix typo (envvar name should be all upper case)

tools/menuconfig.py

@@ -30,6 +30,10 @@ import shutil
 import hashlib
 import operator
 
+DEFAULT_RTT_PACKAGE_URL = 'https://github.com/RT-Thread/packages.git'
+# you can change the package url by defining RTT_PACKAGE_URL, ex:
+#    export RTT_PACKAGE_URL=https://github.com/Varanda-Labs/packages.git
+
 # make rtconfig.h from .config
 
 def is_pkg_special_config(config_str):
@@ -146,6 +150,8 @@ def touch_env():
         home_dir = os.environ['HOME']
     else:
         home_dir = os.environ['USERPROFILE']
+    
+    package_url = os.getenv('RTT_PACKAGE_URL') or DEFAULT_RTT_PACKAGE_URL
 
     env_dir  = os.path.join(home_dir, '.env')
     if not os.path.exists(env_dir):
@@ -158,7 +164,7 @@ def touch_env():
 
     if not os.path.exists(os.path.join(env_dir, 'packages', 'packages')):
         try:
-            ret = os.system('git clone https://github.com/RT-Thread/packages.git %s' % os.path.join(env_dir, 'packages', 'packages'))
+            ret = os.system('git clone %s %s' % (package_url, os.path.join(env_dir, 'packages', 'packages')))
             if ret != 0:
                 shutil.rmtree(os.path.join(env_dir, 'packages', 'packages'))
                 print("********************************************************************************\n"