Index: trac/web/cgi_frontend.py
===================================================================
--- trac/web/cgi_frontend.py	(revision 1936)
+++ trac/web/cgi_frontend.py	(working copy)
@@ -93,10 +93,10 @@
             raise KeyError(name)
         self.list = filter(lambda x, name=name: x.name != name, self.list)
 
-def run():
+def run(env_path=None):
     locale.setlocale(locale.LC_ALL, '')
 
-    env = open_environment()
+    env = open_environment(env_path)
     req = CGIRequest()
 
     try:
Index: cgi-bin/trac.cgi
===================================================================
--- cgi-bin/trac.cgi	(revision 1936)
+++ cgi-bin/trac.cgi	(working copy)
@@ -22,6 +22,7 @@
 
 try:
     from trac.web import cgi_frontend
+#   set up your TRAC_ENV here, e.g. cgi_frontend.run('C:\\path\\to\\trac.db')
     cgi_frontend.run()
 except Exception, e:
     print 'Content-Type: text/plain\r\n\r\n',