Add global _did_earlybird to allow main_decorator to coexist.

This way you don't get duplicate handlers.

voussoirkit/vlogging.py

@@ -38,6 +38,8 @@ root.setLevel(NOTSET)
 LOUD = 1
 SILENT = 99999999999
 
+_did_earlybird = False
+
 def add_loud(log):
     '''
     Add the `loud` method to the given logger.
@@ -89,7 +91,9 @@ def earlybird_config():
     However, this might have the downside of making your program more difficult
     to debug because sys.argv is permanently altered.
     '''
+    global _did_earlybird
     sys.argv = basic_config_by_argv(sys.argv)
+    _did_earlybird = True
 
 def get_level_by_argv(argv):
     '''
@@ -199,6 +203,11 @@ def main_decorator(main):
     betterhelp.HELPTEXT_EPILOGUES.add(BETTERHELP_EPILOGUE)
     @functools.wraps(main)
     def wrapped(argv, *args, **kwargs):
+        # The reason we don't call basic_config is that another module may have
+        # attached a root handler for another purpose.
+        # However we do check _did_earlybird so that we don't get double
+        # handlers from this module.
+        if not _did_earlybird:
             (level, argv) = get_level_by_argv(argv)
             add_root_handler(level)
         return main(argv, *args, **kwargs)