Avoid duplications

python-modules.sh

@@ -16,12 +16,12 @@ prepend_path:
 if [ ! "X$VIRTUAL_ENV" = X ]; then
   # Once more to get the deactivate
   . $VIRTUAL_ENV/bin/activate
-  pip freeze > requirements.txt
+  pip freeze > system-requirements.txt
   deactivate
 fi
 
 # PIP_REQUIREMENTS & PIP36_REQUIREMENTS come from Python-modules-list
-echo $PIP_REQUIREMENTS | tr \  \\n >> requirements.txt
+echo $PIP_REQUIREMENTS | tr \  \\n > requirements.txt
 if python3 -c 'import sys; exit(0 if 1000*sys.version_info.major + sys.version_info.minor >= 3006 else 1)' && [[ $ARCHITECTURE != slc6* ]]; then
   echo $PIP36_REQUIREMENTS | tr \  \\n >> requirements.txt
 fi
@@ -40,6 +40,7 @@ python3 -m venv --system-site-packages --symlinks $PYTHON_MODULES_INSTALLROOT
 # See also:
 #   https://github.com/scikit-garden/scikit-garden/issues/23
 grep RootInteractive requirements.txt && pip3 install -IU numpy
+pip3 install -IU -r system-requirements.txt
 pip3 install -IU -r requirements.txt
 
 # Major.minor version of Python