using automatic spack env creation

Author: Rafael Sarmiento

docs/tutorial_build_automation.rst

@@ -110,52 +110,36 @@ Here is the test's code:
 
 When :attr:`~reframe.core.pipeline.RegressionTest.build_system` is set to ``'Spack'``, ReFrame will leverage Spack environments in order to build the test code.
 If the environment is not specified by the user, ReFrame will automatically create one inside the stage directory.
-ReFrame treats Spack environments specified by the user as *test resources* so it expects to find them under the test's :attr:`~reframe.core.pipeline.RegressionTest.sourcesdir`, which defaults to ``'src'``.
-Here is the directory structure for the test in this particular example that we show here:
-
-.. code:: console
-
-   tutorials/build_systems/spack/
-   ├── spack_test.py
-   └── src
-       └── myenv
-           └── spack.yaml
-
-
-We could have placed ``spack.yaml`` directly under the ``src/`` directory, in which case we would need to specify ``'.'`` as an environment.
-For reference, here are the contents of ``spack.yaml``:
-
-.. literalinclude:: ../tutorials/build_systems/spack/src/myenv/spack.yaml
+That's the case in this example, where the software to be built is specified through the attribute :attr:`~reframe.core.buildsystems.Spack.specs`
 
+When Spack environments are specified by the user, ReFrame treats them as *test resources* so it expects to find them under the test's :attr:`~reframe.core.pipeline.RegressionTest.sourcesdir`, which defaults to ``'src'``.
 
 As with every other test, ReFrame will copy the test's resources to its stage directory before building it.
-ReFrame will then activate the environment and install the associated specs as in this case.
-Optionally, we can add more specs to the environment by setting the :attr:`~reframe.core.buildsystems.Spack.specs` attribute of the build system.
+ReFrame will then activate the generated environment, add the given specs using the ``spack add`` command  and install them.
 Here is what ReFrame generates as a build script in this example:
 
 .. code:: bash
 
    . "$(spack location --spack-root)/share/spack/setup-env.sh"
-   spack env activate -V -d myenv
+   spack env create -d rfm_spack_env
+   spack env activate -V -d rfm_spack_env
+   spack config add "config:install_tree:root:opt/spack"
+   spack add [email protected]
    spack install
 
-Any additional specs specified inside the ReFrame test will be added using the ``spack add`` command.
 As you might have noticed ReFrame expects that Spack is already installed on the system.
 The packages specified in the environment and the tests will be installed in the test's stage directory, where the environment is copied before building.
 Here is the stage directory structure:
 
 .. code:: console
 
    stage/generic/default/builtin/BZip2SpackCheck/
-   ├── myenv
+   ├── rfm_spack_env
    │   ├── spack
-   │   │   ├── opt
-   │   │   │   └── spack
-   │   │   │       ├── bin
-   │   │   │       └── darwin-catalina-skylake
-   │   │   └── share
-   │   │       └── spack
-   │   │           └── modules
+   │   │   └── opt
+   │   │       └── spack
+   │   │           ├── bin
+   │   │           └── darwin-catalina-skylake
    │   ├── spack.lock
    │   └── spack.yaml
    ├── rfm_BZip2SpackCheck_build.err
@@ -172,7 +156,9 @@ Finally, here is the generated run script that ReFrame uses to run the test, onc
 
    #!/bin/bash
    . "$(spack location --spack-root)/share/spack/setup-env.sh"
-   spack env activate -V -d myenv
+   spack env create -d rfm_spack_env
+   spack env activate -V -d rfm_spack_env
+   spack load [email protected]
    bzip2 --help
 
 From this point on, sanity and performance checking are exactly identical to any other ReFrame test.

tutorials/build_systems/spack/spack_test.py

@@ -18,7 +18,6 @@ class BZip2SpackCheck(rfm.RegressionTest):
 
     @run_before('compile')
     def setup_build_system(self):
-        self.build_system.environment = 'myenv'
         self.build_system.specs = ['[email protected]']
 
     @sanity_function