Starting on packaging docs.

lib/spack/docs/basic_usage.rst

+.. _basic_usage:
+
 Basic usage
 =====================
 
@@ -564,76 +566,3 @@ add a version specifier to the spec:
 
 Notice that the package versions that provide insufficient MPI
 versions are now filtered out.
-
-
-Package lifecycle
-------------------------------
-
-``spack install`` command performs a number of tasks before it finally
-installs each package.  It downloads an archive, expands it in a
-temporary directory, and then performs the installation.  Spack has
-several commands that allow finer-grained control over each stage of
-the build process.
-
-
-``spack fetch``
-~~~~~~~~~~~~~~~~~
-
-The first step of ``spack install``.  Takes a spec and determines the
-correct download URL to use for the requested package version, then
-downloads the archive, checks it against an MD5 checksum, and stores
-it in a staging directory if the check was successful.  The staging
-directory will be located under ``$SPACK_HOME/var/spack``.
-
-When run after the archive has already been downloaded, ``spack
-fetch`` is idempotent and will not download the archive again.
-
-``spack stage``
-~~~~~~~~~~~~~~~~~
-
-The second step in ``spack install`` after ``spack fetch``.  Expands
-the downloaded archive in its temporary directory, where it will be
-built by ``spack install``.  Similar to ``fetch``, if the archive has
-already been expanded,  ``stage`` is idempotent.
-
-``spack clean``
-~~~~~~~~~~~~~~~~~
-
-There are several variations of ``spack clean``.  With no arguments,
-``spack clean`` runs ``make clean`` in the expanded archive directory.
-This is useful if an attempted build failed, and something needs to be
-changed to get a package to build.  If a particular package does not
-have a ``make clean`` target, this will do nothing.
-
-``spack clean -w / --work``
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Deletes the entire build directory and re-expands it from the downloaded
-archive. This is useful if a package does not support a proper ``make clean``
-target.
-
-``spack clean -d / --dist``
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Deletes the build directory *and* the downloaded archive.  If
-``fetch``, ``stage``, or ``install`` are run again after this, the
-process will start from scratch, and the archive archive will be
-downloaded again.  Useful if somehow a bad archive is downloaded
-accidentally and needs to be cleaned out of the staging area.
-
-``spack purge``
-~~~~~~~~~~~~~~~~~
-
-Cleans up *everything* in the build directory.  You can use this to
-recover disk space if temporary files from interrupted or failed
-installs accumulate in the staging area.
-
-
-Dirty Installs
-~~~~~~~~~~~~~~~~~~~
-
-By default, ``spack install`` will delete the staging area once a
-pacakge has been successfully built and installed, *or* if an error
-occurs during the build.  Use ``spack install --dirty`` or ``spack
-install -d`` to leave the build directory intact.  This allows you to
-inspect the build directory and potentially fix the build.  You can
-use ``purge`` or ``clean`` later to get rid of the unwanted temporary
-files.

lib/spack/docs/conf.py

@@ -19,7 +19,8 @@
 sys.path.insert(0, os.path.abspath('exts'))
 
 # Add the Spack bin directory to the path so that we can use its output in docs.
-os.environ['PATH'] += os.pathsep + '../../../bin'
+os.environ['SPACK_ROOT'] = '../../..'
+os.environ['PATH'] += os.pathsep + '$SPACK_ROOT/bin'
 
 # Set an environment variable so that colify will print output like it would to
 # a terminal.

lib/spack/docs/packaging_guide.rst

 Packaging Guide
 =====================
 
+This guide is intended for developers or administrators who want to
+*package* their software so that Spack can install it.  We assume that
+you have at least some familiarty with Python, and that you've read
+the :ref:`guide for regular users <basic_usage>`, especially the part
+about *specs*.
+
 
 Package files
 -------------------------
 
+There are two parts of Spack, a language for describing builds of
+software (*specs*), and *packages*: Python modules thatactually build
+the software.  A package essentially takes a spec and implements it
+for a particular piece of software.  It allows a developer to
+encapsulate build logic for different versions, compilers, and
+platforms in one place, and it is designed to make things easy for
+you, the packager, as much as possible.
 
-Dependencies
--------------------------
+Packages in spack live in ``$prefix/lib/spack/spack/packages``:
 
+.. command-output::  cd $SPACK_ROOT/lib/spack/spack/packages;  ls *.py
+   :shell:
+   :ellipsis: 5
 
-Virtual dependencies
+
+Package lifecycle
+------------------------------
+
+``spack install`` command performs a number of tasks before it finally
+installs each package.  It downloads an archive, expands it in a
+temporary directory, and then performs the installation.  Spack has
+several commands that allow finer-grained control over each stage of
+the build process.
+
+
+``spack fetch``
+~~~~~~~~~~~~~~~~~
+
+The first step of ``spack install``.  Takes a spec and determines the
+correct download URL to use for the requested package version, then
+downloads the archive, checks it against an MD5 checksum, and stores
+it in a staging directory if the check was successful.  The staging
+directory will be located under ``$SPACK_HOME/var/spack``.
+
+When run after the archive has already been downloaded, ``spack
+fetch`` is idempotent and will not download the archive again.
+
+``spack stage``
+~~~~~~~~~~~~~~~~~
+
+The second step in ``spack install`` after ``spack fetch``.  Expands
+the downloaded archive in its temporary directory, where it will be
+built by ``spack install``.  Similar to ``fetch``, if the archive has
+already been expanded,  ``stage`` is idempotent.
+
+``spack clean``
+~~~~~~~~~~~~~~~~~
+
+There are several variations of ``spack clean``.  With no arguments,
+``spack clean`` runs ``make clean`` in the expanded archive directory.
+This is useful if an attempted build failed, and something needs to be
+changed to get a package to build.  If a particular package does not
+have a ``make clean`` target, this will do nothing.
+
+``spack clean -w / --work``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Deletes the entire build directory and re-expands it from the downloaded
+archive. This is useful if a package does not support a proper ``make clean``
+target.
+
+``spack clean -d / --dist``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Deletes the build directory *and* the downloaded archive.  If
+``fetch``, ``stage``, or ``install`` are run again after this, the
+process will start from scratch, and the archive archive will be
+downloaded again.  Useful if somehow a bad archive is downloaded
+accidentally and needs to be cleaned out of the staging area.
+
+``spack purge``
+~~~~~~~~~~~~~~~~~
+
+Cleans up *everything* in the build directory.  You can use this to
+recover disk space if temporary files from interrupted or failed
+installs accumulate in the staging area.
+
+
+Dirty Installs
+~~~~~~~~~~~~~~~~~~~
+
+By default, ``spack install`` will delete the staging area once a
+pacakge has been successfully built and installed, *or* if an error
+occurs during the build.  Use ``spack install --dirty`` or ``spack
+install -d`` to leave the build directory intact.  This allows you to
+inspect the build directory and potentially fix the build.  You can
+use ``purge`` or ``clean`` later to get rid of the unwanted temporary
+files.
+
+
+
+Dependencies
 -------------------------
 
 
+
 Virtual dependencies
 -------------------------