Explicitly specify the python interpreter and the config file.

slapos/rebootstrap/__init__.py

@@ -70,6 +70,20 @@ Buildout will be restarted automatically to have this change applied.
       if 'install' in args:
         args =  args[:args.index('install')]
 
+      # explicitly specify the config file location by absolute path
+      if '-c' not in args:
+        config_file = os.path.abspath(os.path.join(
+          os.curdir, 'buildout.cfg'))
+        args.extend(['-c', config_file])
+      else:
+        config_file = args[args.index('-c') + 1]
+        if not zc.buildout.buildout._isurl(config_file):
+          config_file = os.path.abspath(config_file)
+          args[args.index('-c') + 1] = config_file
+
+      # explicitly invoke with the current python interpreter
+      args.insert(0, sys.executable)
+
       # remove rebootstrap extension, which is not needed in rebootstrap part
       extension_list = self.buildout['buildout']['extensions'].split()
       extension_list = [q.strip() for q in extension_list if q.strip() != \