Fix build_python_environment.sh adding a new python variable in the...

Fix build_python_environment.sh adding a new python variable in the configuration file. Also loading the first occurrence of python in case of multiple matches.

conf/common/build.yml

@@ -15,6 +15,7 @@ spack:
 python_environment:
   # Name of the virtual environment in the remote platform experiment folder
   folder_name: python_environment
+  python_version: "3.8:"   # In spack notation use x: to indicate at least x
   requirements:
     # Because there's an issue with numba, for now we need to keep a specific version of numpy
     - numpy==1.23

templates/common/build_python_environment.sh

@@ -2,10 +2,11 @@
 # TODO: What do we do to ensure that these variables are defined in the proj file?
 WORKDIR=%HPCROOTDIR%
 ICON_VERSION=%ICON_VERSION%
-SPACK_URL=%spack.url%
-SPACK_BRANCH=%spack.branch%
-SPACK_COMPILER=%spack.compiler%
+SPACK_URL=%SPACK.URL%
+SPACK_BRANCH=%SPACK.BRANCH%
+SPACK_COMPILER=%SPACK.COMPILER%
 
+PYTHON_VERSION=%PYTHON_ENVIRONMENT.PYTHON_VERSION%
 # Go to the working directory
 cd ${WORKDIR}
 
@@ -14,16 +15,16 @@ load_spack "%spack.init%" "%spack.root%" "%spack.url%" "%spack.branch%" "%spack.
 
 
 # Use spack to get a recent enough version of python3
-if [ $(spack find python@3.8: &>/dev/null ) ]; then
-  echo "python@3.8: already installed!"
+if [ $(spack find python@${PYTHON_VERSION}: &>/dev/null ) ]; then
+  echo "python@${PYTHON_VERSION} already installed!"
 else
   echo "Installing a version of python3"
   # Compile openmpi with schedulers=slurm
-  spack install python@3.8:
+  spack install python@${PYTHON_VERSION}
 fi
 
 # Load the python module
-spack load python
+spack load --first python@${PYTHON_VERSION}
 
 PYTHON_ENVIRONMENT_FOLDER=%python_environment.folder_name%