docs: add example for an external module in packages.yaml

Add an example of a 'modules:' entry for an external package in
packages.yaml.  The 'External Packages' section of 'Build
Customization' mentions 'paths:' and 'modules:' and gives an
example of paths, but not modules.
This commit is contained in:
Mark W. Krentel 2019-06-05 14:57:47 -05:00 committed by Peter Scheibel
parent 5873beb83f
commit 8aa8b50f91

View file

@ -66,8 +66,18 @@ This example lists three installations of OpenMPI, one built with GCC,
one built with GCC and debug information, and another built with Intel.
If Spack is asked to build a package that uses one of these MPIs as a
dependency, it will use the pre-installed OpenMPI in
the given directory. ``packages.yaml`` can also be used to specify modules
to load instead of the installation prefixes.
the given directory. Note that the specified path is the top-level
install prefix, not the ``bin`` subdirectory.
``packages.yaml`` can also be used to specify modules to load instead
of the installation prefixes. The following example says that module
``CMake/3.7.2`` provides cmake version 3.7.2.
.. code-block:: yaml
cmake:
modules:
cmake@3.7.2: CMake/3.7.2
Each ``packages.yaml`` begins with a ``packages:`` token, followed
by a list of package names. To specify externals, add a ``paths`` or ``modules``