title: PackagesNotFoundError: The following packages are not available from current channels. How to solve?
body: <p>Since I'm new to the field, I'm posing this question, although there are already some partial answers. I don't know the concrete solution to my problem.
  I'm trying to install dependencies for executing a code sent by my university supervisor by executing</p>
  <p><code>conda install --yes --file requirements.txt</code></p>
  <p>Then I get the following error message:</p>
  <pre><code>Collecting package metadata (repodata.json): done
  Solving environment: failed with initial frozen solve. Retrying with flexible solve.
  
  PackagesNotFoundError: The following packages are not available from current channels:
  
    - click-default-group==1.2.2
    - profiling==0.1.3
    - jupyter-console==6.1.0
    - mypy-extensions==0.4.3
    - tables==3.6.1
    - numpy==1.18.3
    - ipython-genutils==0.2.0
    - jupyter-core==4.6.3
    - prometheus-client==0.7.1
    - torch==1.4.0
    - torchvision==0.5.0
    - opencv-python==4.2.0.34
    - jupyter-client==6.1.2
    - valuedispatch==0.0.1
    - nbformat==5.0.5
  
  Current channels:
  
    - 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/conda-forge/linux-64
    - https://conda.anaconda.org/conda-forge/noarch 
  </code></pre>
  <p>There was a solution suggested by using an YAML-file instead of the .txt, but I'm not quite sure how to implement this.</p>
  <p>Best</p>
  <p>Edit:
  The content of the requirements.txt is (although quite long):</p>
  <pre><code>appdirs==1.4.4
  astroid==2.3.3
  attrs==19.3.0
  autopep8==1.5.2
  backcall==0.1.0
  black==19.10b0
  bleach==3.1.4
  certifi==2019.11.28
  chardet==3.0.4
  click==7.1.2
  click-default-group==1.2.2
  ConfigArgParse==1.2.3
  configparser==5.0.0
  cycler==0.10.0
  Cython==0.29.17
  decorator==4.4.2
  deepdish==0.3.6
  defusedxml==0.6.0
  entrypoints==0.3
  faiss-cpu==1.6.3
  faiss-gpu==1.6.3
  h5py==2.10.0
  hdbscan==0.8.26
  idna==2.9
  ipykernel==5.2.0
  ipython==7.13.0
  ipython-genutils==0.2.0
  ipywidgets==7.5.1
  isort==4.3.21
  jedi==0.16.0
  Jinja2==2.11.1
  joblib==0.14.1
  jsonschema==3.2.0
  jupyter==1.0.0
  jupyter-client==6.1.2
  jupyter-console==6.1.0
  jupyter-core==4.6.3
  kiwisolver==1.2.0
  lazy-object-proxy==1.4.3
  llvmlite==0.31.0
  MarkupSafe==1.1.1
  matplotlib==3.2.1
  mccabe==0.6.1
  mistune==0.8.4
  mypy==0.770
  mypy-extensions==0.4.3
  nbconvert==5.6.1
  nbformat==5.0.5
  notebook==6.0.3
  numba==0.48.0
  numexpr==2.7.1
  numpy==1.18.3
  opencv-python==4.2.0.34
  pandas==1.0.3
  pandocfilters==1.4.2
  parso==0.6.2
  pathspec==0.8.0
  pexpect==4.8.0
  pickleshare==0.7.5
  Pillow==7.1.1
  profiling==0.1.3
  prometheus-client==0.7.1
  prompt-toolkit==3.0.5
  protobuf==3.11.3
  ptyprocess==0.6.0
  pycodestyle==2.5.0
  Pygments==2.6.1
  pylint==2.4.4
  pyparsing==2.4.6
  pyrsistent==0.16.0
  python-dateutil==2.8.1
  pytz==2019.3
  PyYAML==5.3.1
  pyzmq==19.0.0
  qtconsole==4.7.2
  QtPy==1.9.0
  regex==2020.5.7
  requests==2.23.0
  scikit-learn==0.22.2.post1
  scipy==1.4.1
  seaborn==0.10.0
  Send2Trash==1.5.0
  six==1.14.0
  tables==3.6.1
  tensorboardX==2.0
  terminado==0.8.3
  testpath==0.4.4
  toml==0.10.0
  torch==1.4.0
  torchvision==0.5.0
  tornado==6.0.4
  tqdm==4.45.0
  traitlets==4.3.3
  typed-ast==1.4.1
  typing-extensions==3.7.4.2
  umap-learn==0.3.10
  urllib3==1.25.8
  urwid==2.1.0
  valuedispatch==0.0.1
  wcwidth==0.1.9
  webencodings==0.5.1
  widgetsnbextension==3.5.1
  wrapt==1.11.2
  </code></pre>