Unable to install older wxPython within virtualenv

Question

Within a virtualenv built off Python 2.6.6, I'm trying to pip install the 2.8.10.1 2.6 unicode dmg found here thus:

pip install -Iv http://sourceforge.net/projects/wxpython/files/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg/download

Granted, the URL is a bit of a guess.

I get (dividing the log in two):

MacBook-Pro-de-Pyderman:Pyderman$ pip install -Iv http://sourceforge.net/projects/wxpython/files/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg/download -U --trusted-host sourceforge.net
Collecting http://sourceforge.net/projects/wxpython/files/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg/download
  Starting new HTTP connection (1): sourceforge.net
  "GET /projects/wxpython/files/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg/download HTTP/1.1" 302 519
  Starting new HTTP connection (1): downloads.sourceforge.net
  "GET /project/wxpython/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg?r=&ts=1452906240&use_mirror=superb-dca2 HTTP/1.1" 302 433
  Starting new HTTP connection (1): superb-dca2.dl.sourceforge.net
  "GET /project/wxpython/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg HTTP/1.1" 200 39136817
  Downloading http://sourceforge.net/projects/wxpython/files/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg/download (39.1MB)
  Downloading from URL http://sourceforge.net/projects/wxpython/files/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg/download
    100% |████████████████████████████████| 39.1MB 1.9MB/s 
  Cannot unpack file /private/var/folders/t3/yhd5b6lj2cz_b82qzw4zcwh40000gn/T/pip-mLGthu-unpack/download.dmg (downloaded from /var/folders/t3/yhd5b6lj2cz_b82qzw4zcwh40000gn/T/pip-FRcExS-build, content-type: application/x-apple-diskimage); cannot detect archive format
Cleaning up...
Cannot determine archive format of /var/folders/t3/yhd5b6lj2cz_b82qzw4zcwh40000gn/T/pip-FRcExS-build

-

Exception information:Pyderman
Traceback (most recent call last):
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/basecommand.py", line 211, in main
    status = self.run(options, args)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/commands/install.py", line 305, in run
    wb.build(autobuilding=True)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/wheel.py", line 705, in build
    self.requirement_set.prepare_files(self.finder)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/req/req_set.py", line 334, in prepare_files
    functools.partial(self._prepare_file, finder))
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/req/req_set.py", line 321, in _walk_req_to_install
    more_reqs = handler(req_to_install)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/req/req_set.py", line 491, in _prepare_file
    session=self.session)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/download.py", line 825, in unpack_url
    session,
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/download.py", line 677, in unpack_http_url
    unpack_file(from_path, location, content_type, link)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/utils/__init__.py", line 665, in unpack_file
    'Cannot determine archive format of %s' % location
InstallationError: Cannot determine archive format of /var/folders/t3/yhd5b6lj2cz_b82qzw4zcwh40000gn/T/pip-FRcExS-build
Starting new HTTPS connection (1): pypi.python.org
/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
There was an error checking the latest version of pip
Traceback (most recent call last):
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/utils/outdated.py", line 126, in pip_version_check
    headers={"Accept": "application/json"},
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/_vendor/requests/sessions.py", line 477, in get
    return self.request('GET', url, **kwargs)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/download.py", line 373, in request
    return super(PipSession, self).request(method, url, *args, **kwargs)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/_vendor/requests/sessions.py", line 465, in request
    resp = self.send(prep, **send_kwargs)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/_vendor/requests/sessions.py", line 573, in send
    r = adapter.send(request, **kwargs)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/_vendor/cachecontrol/adapter.py", line 46, in send
    resp = super(CacheControlAdapter, self).send(request, **kw)
  File "/Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-packages/pip/_vendor/requests/adapters.py", line 431, in send
    raise SSLError(e, request=request)
SSLError: [Errno 1] _ssl.c:490: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

Is "There was an error checking the latest version of pip" significant?

pip is the virtualenv's own:

/Users/Pyderman/Downloads/Pyderman/venv/bin/pip --version
pip 7.1.2 from /Users/Pyderman/Downloads/Pyderman/venv/lib/python2.6/site-    
packages (python 2.6)

Answer 1

I don't think the error checking version is significant to your problem (this is just pip trying to update itself) but it is causing the error. Perhaps the older version of Python doesn't support the required SSL settings? You can disable this update check using:

pip install -Iv http://sourceforge.net/projects/wxpython/files/wxPython/2.8.10.1/wxPython2.8-osx-unicode-2.8.10.1-universal-py2.6.dmg/download --disable-pip-version-check