# Got error "gaierror: \[Errno -2\] Name or service not known" when run py.test

**URL:** <https://discourse.mitmproxy.org/t/got-error-gaierror-errno-2-name-or-service-not-known-when-run-py-test/129>\
**Category:** Uncategorized\
**Created:** [August 5, 2016, 2:10am UTC](https://discourse.mitmproxy.org/t/got-error-gaierror-errno-2-name-or-service-not-known-when-run-py-test/129 "2016-08-05T02:10:38Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![ndhydev](https://avatars.discourse-cdn.com/v4/letter/n/b77776/32.png) [@ndhydev](https://discourse.mitmproxy.org/u/ndhydev)\
**Post date:** [August 5, 2016, 2:10am UTC](https://discourse.mitmproxy.org/t/got-error-gaierror-errno-2-name-or-service-not-known-when-run-py-test/129/1 "2016-08-05T02:10:38Z")

</div>

I am trying to install mitmproxy following the [readme.md](http://readme.md) at master. After the [dev.sh](http://dev.sh) finished, I run py.test and got this error “aierror: [Errno -2] Name or service not known”. I am not familiar with python, so could you help me how to solve this?  
This is the full terminal output of py.test.

```
(venv) Vostro-2420 ~/mitmproxy $ py.test
============================= test session starts =====est=========================
platform linux2 -- Python 2.7.12, pytest-2.9.2, py-1.4.31, pluggy-0.3.1
rootdir: /home/hynguyen/mitmproxy, inifile: setup.cfg
plugins: timeout-1.0.0, cov-2.3.0, xdist-1.14
collected 908 items 

test/mitmproxy/test_addons.py .
test/mitmproxy/test_app.py ..
test/mitmproxy/test_cmdline.py ......
test/mitmproxy/test_contentview.py ...................
test/mitmproxy/test_contrib_tnetstring.py .......
test/mitmproxy/test_controller.py ..........
test/mitmproxy/test_custom_contentview.py .
test/mitmproxy/test_dump.py ...............
test/mitmproxy/test_examples.py ........
test/mitmproxy/test_filt.py ..........................................
test/mitmproxy/test_flow.py .........................................................
test/mitmproxy/test_flow_export.py ..................
test/mitmproxy/test_flow_format_compat.py ..
test/mitmproxy/test_fuzzing.py ...
test/mitmproxy/test_optmanager.py .....
test/mitmproxy/test_platform_pf.py .
test/mitmproxy/test_protocol_http1.py .....
test/mitmproxy/test_protocol_http2.py ............
test/mitmproxy/test_proxy.py ..................
test/mitmproxy/test_proxy_config.py ..
test/mitmproxy/test_server.py ......................................................................................................
test/mitmproxy/test_stateobject.py ...
test/mitmproxy/test_utils.py ..
test/mitmproxy/test_web_app.py ....
test/mitmproxy/test_web_master.py .
test/mitmproxy/builtins/test_anticache.py .
test/mitmproxy/builtins/test_anticomp.py .
test/mitmproxy/builtins/test_dumper.py ..
test/mitmproxy/builtins/test_filestreamer.py .
test/mitmproxy/builtins/test_replace.py ..
test/mitmproxy/builtins/test_script.py ...s.........
test/mitmproxy/builtins/test_setheaders.py ..
test/mitmproxy/builtins/test_stickyauth.py .
test/mitmproxy/builtins/test_stickycookie.py .........
test/mitmproxy/console/test_common.py .
test/mitmproxy/console/test_help.py ..
test/mitmproxy/console/test_master.py ........
test/mitmproxy/console/test_palettes.py .
test/mitmproxy/console/test_pathedit.py ...
test/mitmproxy/script/test_concurrent.py ..
test/netlib/test_basetypes.py .
test/netlib/test_certutils.py ..........
test/netlib/test_debug.py ....
test/netlib/test_encoding.py .....
test/netlib/test_human.py .....
test/netlib/test_multidict.py .........................
test/netlib/test_socks.py ..............
test/netlib/test_strutils.py .........
test/netlib/test_tcp.py ...E...................................................
test/netlib/test_utils.py ..
test/netlib/test_version_check.py ..
test/netlib/test_wsgi.py ......
test/netlib/http/test_authentication.py ...........
test/netlib/http/test_cookies.py .........
test/netlib/http/test_headers.py .......
test/netlib/http/test_message.py ......................
test/netlib/http/test_multipart.py .
test/netlib/http/test_request.py .......s.......................
test/netlib/http/test_response.py ............
test/netlib/http/test_status_codes.py .
test/netlib/http/test_url.py ......
test/netlib/http/test_user_agents.py .
test/netlib/http/http1/test_assemble.py .........
test/netlib/http/http1/test_read.py ..................................
test/netlib/websockets/test_websockets.py .........
test/pathod/test_language_actions.py .................
test/pathod/test_language_base.py ........................
test/pathod/test_language_generators.py ...
test/pathod/test_language_http.py .................................
test/pathod/test_language_http2.py ........................
test/pathod/test_language_websocket.py ..........
test/pathod/test_language_writer.py ......
test/pathod/test_log.py .
test/pathod/test_pathoc.py ....................
test/pathod/test_pathoc_cmdline.py .
test/pathod/test_pathod.py .................................................
test/pathod/test_pathod_cmdline.py ..
test/pathod/test_protocols_http2.py ...........................
test/pathod/test_test.py ...
test/pathod/test_utils.py ..

==================================== ERRORS ====================================
__________________ERROR at setup of TestServerIPv6.test_echo__________________

cls = <class 'test.netlib.test_tcp.TestServerIPv6'>, kwargs = {}

    @classmethod
    def setup_class(cls, **kwargs):
        cls.q = queue.Queue()
> s = cls.makeserver(**kwargs)

test/netlib/tservers.py:96: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
test/netlib/tservers.py:103: in makeserver
    return _TServer(cls.ssl, cls.q, cls.handler, cls.addr, **kwargs)
test/netlib/tservers.py:34: in __init__
    tcp.TCPServer. __init__ (self, addr)
netlib/tcp.py:898: in __init__
    self.socket.bind(self.address())
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

name = 'bind', self = <socket._socketobject object at 0x7fbd146654b0>
args = (('localhost', 0),)

    def meth(name,self,*args):
> return getattr(self._sock,name)(*args)
E gaierror: [Errno -2] Name or service not known

/usr/lib/python2.7/socket.py:228: gaierror
====== 905 passed, 2 skipped, 1 pytest-warnings, 1 error in 88.63 seconds ======
```

---

<div class="post-metadata">

**Author:** ![ndhydev](https://avatars.discourse-cdn.com/v4/letter/n/b77776/32.png) [@ndhydev](https://discourse.mitmproxy.org/u/ndhydev)\
**Post date:** [August 5, 2016, 2:41am UTC](https://discourse.mitmproxy.org/t/got-error-gaierror-errno-2-name-or-service-not-known-when-run-py-test/129/2 "2016-08-05T02:41:51Z")

</div>

When I try to run the py.test in sudo mode.  
sudo -H py.test  
The terminal stuck for a long time at test\_server.py:  
========================================== test session starts ===========================================  
platform linux2 – Python 2.7.12, pytest-2.9.2, py-1.4.31, pluggy-0.3.1  
rootdir: /home/hynguyen/mitmproxy, inifile: setup.cfg  
plugins: timeout-1.0.0, cov-2.3.0, xdist-1.14  
collected 908 items

```
test/mitmproxy/test_addons.py .
test/mitmproxy/test_app.py ..
test/mitmproxy/test_cmdline.py ......
test/mitmproxy/test_contentview.py ...................
test/mitmproxy/test_contrib_tnetstring.py .......
test/mitmproxy/test_controller.py ..........
test/mitmproxy/test_custom_contentview.py .
test/mitmproxy/test_dump.py ...............
test/mitmproxy/test_examples.py ........
test/mitmproxy/test_filt.py ..........................................
test/mitmproxy/test_flow.py .........................................................
test/mitmproxy/test_flow_export.py ..................
test/mitmproxy/test_flow_format_compat.py ..
test/mitmproxy/test_fuzzing.py ...
test/mitmproxy/test_optmanager.py .....
test/mitmproxy/test_platform_pf.py .
test/mitmproxy/test_protocol_http1.py .....
test/mitmproxy/test_protocol_http2.py ............
test/mitmproxy/test_proxy.py ..............F...
test/mitmproxy/test_proxy_config.py ..
test/mitmproxy/test_server.py .
```

---

<div class="post-metadata">

**Author:** ![ujjwal96](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mitmproxy.org/ujjwal96/32/111_2.png) [@ujjwal96](https://discourse.mitmproxy.org/u/ujjwal96)\
**Post date:** [January 28, 2017, 9:28am UTC](https://discourse.mitmproxy.org/t/got-error-gaierror-errno-2-name-or-service-not-known-when-run-py-test/129/4 "2017-01-28T09:28:17Z")

</div>

I know this late but I too had the same error today. Check the contents of your /etc/hosts file ‘localhost’ may not be written in front of ::1 . I had ip6-localhost  
To fix this just add ‘localhost’ to the line starting with ::1