title: Conda cannot find packages to install
body: <p>I have been using conda for quite some time without problems, and just now I started to a <code>PackagesNotFoundError</code> error when ever I try to install a package. For example if I try:</p>
  <pre><code>conda install scipy --channel conda-forge
  </code></pre>
  <p>I am getting this:</p>
  <pre><code>PackagesNotFoundError: The following packages are not available from current channels:
  
    - scipy
  
  Current channels:
  
    - https://conda.anaconda.org/conda-forge/linux-64
    - https://conda.anaconda.org/conda-forge/noarch
    - https://conda.anaconda.org/bioconda/linux-64
    - https://conda.anaconda.org/bioconda/noarch
    - https://repo.anaconda.com/pkgs/main/linux-64
    - https://repo.anaconda.com/pkgs/main/noarch
    - https://repo.anaconda.com/pkgs/r/linux-64
    - https://repo.anaconda.com/pkgs/r/noarch
    - https://conda.anaconda.org/cgat/linux-64
    - https://conda.anaconda.org/cgat/noarch
  
  To search for alternate channels that may provide the conda package you're
  looking for, navigate to
  
      https://anaconda.org
  
  and use the search bar at the top of the page.
  </code></pre>
  <p>But then if I use anaconda to search this package, I can see it at conda-forge channel. Then even if I use the command suggested by anaconda; <code>conda install --channel https://conda.anaconda.org/conda-forge scipy</code>, I get the same error.</p>
  <p>On an attempt to solve the issue, I reinstalled a new version of conda, but the issue persists and I can't install anything with conda at the moment. Can someone give me a clue of what is going wrong?</p>
  <p><strong>UPDATE</strong></p>
  <p>As recommended by some suggestions</p>
  <p>I have run:</p>
  <pre><code>conda clean -all
  conda clean --index-cache
  conda update conda
  </code></pre>
  <p>And I still have the same issue</p>
  <p>The version of my current conda is 4.8.2</p>
  <p><strong>UPDATE 2</strong></p>
  <p>@merv suggested to run with the vervose flag, so I ran <code>conda search -c conda-forge scipy -vvv</code> and got this:</p>
  <pre><code>DEBUG conda.gateways.logging:set_verbosity(231): verbosity set to 3
  Loading channels: ...working... TRACE conda.gateways.disk.test:file_path_is_writable(25): checking path is writable /path/miniconda/pkgs/urls.txt
  DEBUG conda.core.package_cache_data:_check_writable(259): package cache directory '/path/miniconda/pkgs' writable: True
  INFO conda.core.subdir_data:query_all(94): Ignoring the following channel urls because mode is offline.
    - https://conda.anaconda.org/conda-forge/linux-64
    - https://conda.anaconda.org/conda-forge/noarch
    - https://conda.anaconda.org/bioconda/linux-64
    - https://conda.anaconda.org/bioconda/noarch
    - https://repo.anaconda.com/pkgs/main/linux-64
    - https://repo.anaconda.com/pkgs/main/noarch
    - https://repo.anaconda.com/pkgs/r/linux-64
    - https://repo.anaconda.com/pkgs/r/noarch
    - https://conda.anaconda.org/cgat/linux-64
    - https://conda.anaconda.org/cgat/noarch
  done
  No match found for: scipy. Search: *scipy*
  INFO conda.core.subdir_data:query_all(94): Ignoring the following channel urls because mode is offline.
    - https://conda.anaconda.org/conda-forge/linux-64
    - https://conda.anaconda.org/conda-forge/noarch
    - https://conda.anaconda.org/bioconda/linux-64
    - https://conda.anaconda.org/bioconda/noarch
    - https://repo.anaconda.com/pkgs/main/linux-64
    - https://repo.anaconda.com/pkgs/main/noarch
    - https://repo.anaconda.com/pkgs/r/linux-64
    - https://repo.anaconda.com/pkgs/r/noarch
    - https://conda.anaconda.org/cgat/linux-64
    - https://conda.anaconda.org/cgat/noarch
  Traceback (most recent call last):
    File &quot;/path/miniconda/lib/python3.6/site-packages/conda/exceptions.py&quot;, line 1079, in __call__
      return func(*args, **kwargs)
    File &quot;/path/miniconda/lib/python3.6/site-packages/conda/cli/main.py&quot;, line 84, in _main
      exit_code = do_call(args, p)
    File &quot;/path/miniconda/lib/python3.6/site-packages/conda/cli/conda_argparse.py&quot;, line 82, in do_call
      return getattr(module, func_name)(args, parser)
    File &quot;/path/miniconda/lib/python3.6/site-packages/conda/cli/main_search.py&quot;, line 90, in execute
      raise PackagesNotFoundError((text_type(spec),), channels_urls)
  conda.exceptions.PackagesNotFoundError: The following packages are not available from current channels:
  
    - scipy
  
  Current channels:
  
    - https://conda.anaconda.org/conda-forge/linux-64
    - https://conda.anaconda.org/conda-forge/noarch
    - https://conda.anaconda.org/bioconda/linux-64
    - https://conda.anaconda.org/bioconda/noarch
    - https://repo.anaconda.com/pkgs/main/linux-64
    - https://repo.anaconda.com/pkgs/main/noarch
    - https://repo.anaconda.com/pkgs/r/linux-64
    - https://repo.anaconda.com/pkgs/r/noarch
    - https://conda.anaconda.org/cgat/linux-64
    - https://conda.anaconda.org/cgat/noarch
  
  To search for alternate channels that may provide the conda package you're
  looking for, navigate to
  
      https://anaconda.org
  
  and use the search bar at the top of the page.
  </code></pre>
  <p>I think the part that says <code>Ignoring the following channel urls because mode is offline</code> is very likely related with this error since I can't access the packages from any of the channels. However, I still don't know how to change the mode of the urls.</p>