* Split get_compiler_version into two functions:
  get_compiler_version_output runs the compiler with the relevant
  option to print the version; extract_version_from_output determines
  the version by examining this output. This makes it easier to test
  the customized version detection for each compiler. Users can
  customize this by overriding the following:
  * version_argument: this is the argument that tells the compiler to
    print its version. It assumes that the compiler will report its
	version if invoked with a single option (like "--version")
  * version_regex: the regular expression used to extract the version
    from the compiler argument. This assumes that a regular
	expression is sufficient to extract the version, and that the
	version can be extracted from a single capture group (Spack uses
	the first capture group)
  * default_version: allows you to completely override all version
    detection logic
  * get_compiler_version_output: if getting the compiler to report
    its version is more complex than invoking it with a single arg
  * extract_version_from_output: if it is difficult to define a regex
    that can be used to extract the version from the output
* Added tests for version detection of most compilers
* Removed redundant code from xl_r compiler class (by inheriting
  from xl compiler definition)

* adding package to install squashfs for singularity

* dont need os import

Signed-off-by: Vanessa Sochat <vsochat@stanford.edu>

* updating md5 to sha1 for squashfs package

Signed-off-by: Vanessa Sochat <vsochat@stanford.edu>

* two blank lines

Signed-off-by: Vanessa Sochat <vsochat@stanford.edu>

QMCPACK MKL buglet. Now you are able to use the Intel compiler with other BLAS and LAPACK providers, no longer forced to use MKL. (#11019)

Replace the original implementation of the "memoized" decorator with
an implementation that exposes the docstring and arguments of the
wrapped function. This is achieved using functools.wraps.

* add libs property to IntelMkl and IntelParallelStudio
* fix scalapack_libs when MPI is provided by intel-parallel-studio

This provides a mechanism to implement a new Spack command in a
separate directory, and with a small configuration change point Spack
to the new command.

To register the command, the directory must be added to the
"extensions" section of config.yaml. The command directory name must
have the prefix "spack-", and have the following layout:

  spack-X/
    pytest.ini #optional, for testing
    X/
	  cmd/
	    name-of-command1.py
	    name-of-command2.py
	    ...
    tests/ #optional
      conftest.py
	  test_name-of-command1.py
    templates/ #optional jinja templates, if needed

And in config.yaml:

  config:
    extensions:
      - /path/to/spack-X

If the extension includes tests, you can run them via spack by adding
the --extension option, like "spack test --extension=X"

* Newer versions of IBM XL no longer define `__xlC__`, but define `__ibmxl__`
  instead.  This one-line patch fixes this problem in Random123.
* This patch was also provided to the Random123 maintiners
  (Random123@DEShawResearch.com). I don't expect a new release from them for a
  while, so I believe that this patch is the correct path forward (for now).

* preserve the order in which patches are applied by packages (in spite of grouping them by 'when')

* add tests confirming patch order

* initial work to make use of an 'upstream' spack installation: this uses the DB of the upstream installation to check if a package is installed

* need to query upstream dbs when adding new record to local db

* prevent reindexing upstream DBs

* set prefix on specs read from DB based on path stored in install record

* check that Spack does not install packages that are recorded as installed in an upstream db

* externals do not add their path to install records - need to use 'external_path' to get path of upstream externals

* views need to check for upstream installations when linking metadata

* package and spec now calculate upstream installation properties on-demand themselves rather than depending on concretization to set these properties up-front. The added tests for upstream installations don't work with this new strategy so they need to be updated

* only refresh modules for local specs (not those in upstream packages); optionally generate local module files for packages installed upstream

* when a user tries to locate a module file for a package installed upstream, tell them to use the upstream spack instance to locate it

* support recursive upstream databases (allow upstream databases to use their own upstream databases)

* separate upstream config into separate file with its own schema; each entry now also includes a name

* metadata_dir is no longer customizable on a per-instance basis for YamlDirectoryLayout

* treat metadata_dir as an instance variable but dont set it from kwargs; this follows several other hardcoded variables which must be consistent between upstream and downstream DBs. Also update DirectoryLayout.metadata_path to work entirely with Spec.prefix, since Spec.prefix is set from the DB when available (so metadata_path was duplicating that logic)

Prevents infinite recursion caused by sourcing `setup-env.sh` in bashrc

* Add latest libyogrt versions
* Add url_for_version to handle differing url formats for different
  versions
* Add 'scheduler' variant to configure scheduler. Currently only
  slurm can be installed with Spack. A value of 'system' indicates
  to use the scheduler installed on the system

Change the location of the CMake build area from the staged source
directory to the stage base directory.

This change allows CMake packages to refer to the build directory in
setup_environment (e.g. if tests need to have a directory in PATH):
Staging happens after the call to setup_environment(), and if the
stage area does not exist, then spec.stage.source_path returns None.

To accommodate this change, archived files (like config.log for
Autotools packages) are archived relative to the stage base directory
rather than the expanded source directory.

Other packages (those not using CMake) will still use the staged
source directory as the default working directory for builds (and
will still be unable to reference this directory in
setup_environment())

Also add conflicts for PPC

When multiple instances of environment-modules were installed with
different architectures, Spack was not retrieving the installation
appropriate for the current architecture when finding the module
prefix.

* py-prompt-toolkit: Add newer version for required for newer
  py-ipython versions
* py-ipykernel:
  * Add newer py-ipykernel version
  * Depend on py-setuptools so a python egg isn't attempted to be
    built
  * Update dependency for newer py-ipykernel versions
* py-jupyter-console: Remove py-prompt-toolkit dependency since it is
  picked up in py-ipython
* py-ipython:
  * Add missing py-backcall dependency
  * Adjust py-prompt-toolkit dependencies for newer versions of
    ipython
* py-jupyter-notebook: Require newer version of py-ipykernel since
  jupyter is broken with previous versions