AttributeError: 'Extensions' object has no attribute 'get_extension_for_class'

[senis000]

This has happened trying to update conda or install anything with conda.

$conda install mtspec
Fetching package metadata ...An unexpected error has occurred.
Please consider posting the following information to the
conda GitHub issue tracker at:

https://github.com/conda/conda/issues

Current conda install:

           platform : win-64
      conda version : 4.2.13
   conda is private : False
  conda-env version : 4.2.13
conda-build version : 1.18.1
     python version : 3.5.2.final.0
   requests version : 2.12.1
   root environment : C:\Python\Anaconda  (writable)
default environment : C:\Python\Anaconda
   envs directories : C:\Python\Anaconda\envs
      package cache : C:\Python\Anaconda\pkgs
       channel URLs : https://conda.anaconda.org/conda-forge/win-64
                      https://conda.anaconda.org/conda-forge/noarch
                      https://repo.continuum.io/pkgs/free/win-64
                      https://repo.continuum.io/pkgs/free/noarch
                      https://repo.continuum.io/pkgs/pro/win-64
                      https://repo.continuum.io/pkgs/pro/noarch
                      https://repo.continuum.io/pkgs/msys2/win-64
                      https://repo.continuum.io/pkgs/msys2/noarch
        config file : C:\Users\senis\.condarc
       offline mode : False

$ C:\Python\Anaconda\Scripts\conda-script.py install mtspec

Traceback (most recent call last):
  File "C:\Python\Anaconda\lib\site-packages\conda\exceptions.py", line 479,

in conda_exception_handler
return_value = func(*args, **kwargs)
File "C:\Python\Anaconda\lib\site-packages\conda\cli\main.py", line 145, i
n main
exit_code = args.func(args, p)
File "C:\Python\Anaconda\lib\site-packages\conda\cli\main_install.py", lin
e 80, in execute
install(args, parser, 'install')
File "C:\Python\Anaconda\lib\site-packages\conda\cli\install.py", line 238
, in install
prefix=prefix)
File "C:\Python\Anaconda\lib\site-packages\conda\api.py", line 24, in get
index
index = fetch_index(channel_urls, use_cache=use_cache, unknown=unknown)
File "C:\Python\Anaconda\lib\site-packages\conda\fetch.py", line 300, in f
etch_index
repodatas = [(u, f.result()) for u, f in zip(urls, futures)]
File "C:\Python\Anaconda\lib\site-packages\conda\fetch.py", line 300, in <
listcomp>
repodatas = [(u, f.result()) for u, f in zip(urls, futures)]
File "C:\Python\Anaconda\lib\concurrent\futures_base.py", line 405, in re
sult
return self.__get_result()
File "C:\Python\Anaconda\lib\concurrent\futures_base.py", line 357, in __
get_result
raise self._exception
File "C:\Python\Anaconda\lib\concurrent\futures\thread.py", line 55, in ru
n
result = self.fn(*self.args, **self.kwargs)
File "C:\Python\Anaconda\lib\site-packages\conda\fetch.py", line 75, in fu
nc
res = f(*args, **kwargs)
File "C:\Python\Anaconda\lib\site-packages\conda\fetch.py", line 117, in f
etch_repodata
timeout=(6.1, 60))
File "C:\Python\Anaconda\lib\site-packages\requests\sessions.py", line 501
, in get
return self.request('GET', url, **kwargs)
File "C:\Python\Anaconda\lib\site-packages\requests\sessions.py", line 488
, in request
resp = self.send(prep, **send_kwargs)
File "C:\Python\Anaconda\lib\site-packages\requests\sessions.py", line 609
, in send
r = adapter.send(request, **kwargs)
File "C:\Python\Anaconda\lib\site-packages\requests\adapters.py", line 423
, in send
timeout=timeout
File "C:\Python\Anaconda\lib\site-packages\requests\packages\urllib3\conne
ctionpool.py", line 594, in urlopen
chunked=chunked)
File "C:\Python\Anaconda\lib\site-packages\requests\packages\urllib3\conne
ctionpool.py", line 350, in _make_request
self._validate_conn(conn)
File "C:\Python\Anaconda\lib\site-packages\requests\packages\urllib3\conne
ctionpool.py", line 835, in _validate_conn
conn.connect()
File "C:\Python\Anaconda\lib\site-packages\requests\packages\urllib3\conne
ction.py", line 330, in connect
cert = self.sock.getpeercert()
File "C:\Python\Anaconda\lib\site-packages\requests\packages\urllib3\contr
ib\pyopenssl.py", line 324, in getpeercert
'subjectAltName': get_subj_alt_name(x509)
File "C:\Python\Anaconda\lib\site-packages\requests\packages\urllib3\contr
ib\pyopenssl.py", line 171, in get_subj_alt_name
ext = cert.extensions.get_extension_for_class(
AttributeError: 'Extensions' object has no attribute 'get_extension_for_clas
s'

Same as when I tried to update conda (I posted it in #4003) before realizing that is not a problem of updating but with conda itself

[senis000]

I found a solution in:
#3938

[kalefranz]

Duplicate of #3898, #3918, #3929, #3934, and #3935.

[github-actions]

Hi there, thank you for your contribution to Conda!

This issue has been automatically locked since it has not had recent activity after it was closed.

Please open a new issue if needed.