diff -r bb0d5aad761a -r 69acfd2ca11e mercurial/url.py
--- a/mercurial/url.py	Mon Dec 19 02:35:38 2016 +0530
+++ b/mercurial/url.py	Mon Dec 19 02:54:49 2016 +0530
@@ -18,6 +18,7 @@
     error,
     httpconnection as httpconnectionmod,
     keepalive,
+    pycompat,
     sslutil,
     util,
 )
@@ -79,7 +80,8 @@
 
 class proxyhandler(urlreq.proxyhandler):
     def __init__(self, ui):
-        proxyurl = ui.config("http_proxy", "host") or os.getenv('http_proxy')
+        proxyurl = (ui.config("http_proxy", "host") or
+                        pycompat.osgetenv('http_proxy'))
         # XXX proxyauthinfo = None
 
         if proxyurl:
@@ -97,7 +99,7 @@
             no_list.extend([p.lower() for
                             p in ui.configlist("http_proxy", "no")])
             no_list.extend([p.strip().lower() for
-                            p in os.getenv("no_proxy", '').split(',')
+                            p in pycompat.osgetenv("no_proxy", '').split(',')
                             if p.strip()])
             # "http_proxy.always" config is for running tests on localhost
             if ui.configbool("http_proxy", "always"):