*****************************
Keeping AstroConda "Like New"
*****************************

Anaconda's package manager, Conda, will not automatically update unless a newer version of a package is detected during
a routine package installation. Suffice to say, unless you keep your packages up to date with ``conda update``, the
packages installed in your Anaconda distribution will remain relatively static.

Updating AstroConda
===================

The update procedure for AstroConda is relatively straight foward.

.. code-block:: sh

    # Will update all packages
    $ conda update --all

    # Will update packages if a new public release is present
    $ conda update astroconda

(`ref <http://conda.pydata.org/docs/using/pkgs.html#package-update>`__)


Downgrading Packages
====================

Did a recent update break your code? Don't wait around for a bugfix... Keep working. For example, if a bug is introduced
into ``stsci.tool``, you can easily downgrade it to a known-good version:

.. code-block:: sh

    $ conda search stsci.tools
    .  3.4.0.git              py35_6  astroconda
    *  3.4.1.git              py35_0  astroconda

The ``*`` denotes the current version installed locally.

Now the only thing left do is tell Conda to install the previous release of the package:

.. code-block:: sh

    $ conda install stsci.tools=3.4.0

At this point you should be back in business.

(`ref <http://conda.pydata.org/docs/faq.html#managing-packages>`__)


Pinning Packages
================

.. caution:: Pinning packages has the potential to break Conda. Only pin packages as a last resort.

Let's take the previous example one step further... Imagine ``stsci.tools`` is broken, and the hotfix release of ``3.4.2``
only partially solved the original issue. Now what? You still need to receive updates to other packages, but
``stsci.tools`` keeps trying to update back to ``3.4.2`` every time you touch ``conda update``.


.. code-block:: sh

    $ echo "stsci.tools <=3.4.0" > ${CONDA_ENV_PATH}/conda-meta/pinned

From now on, future calls to ``conda update`` will omit ``stsci.tools`` while performing dependency resolution. However,
a clear side-effect of this will also be losing the ability to update packages that depend strictly on version ``3.4.2``.
Although this is not a permanent solution it can prove useful in a bad situation.

(`ref <http://conda.pydata.org/docs/faq.html?highlight=pinning#pinning-packages>`__)