First, you might want to delete the old spack instances if you want to refresh them.
rm -rf /project/g110/spack/user/admin-$slave /project/g110/spack/user/$slave
If you want to recreate them from scratch, don't forget to remove their associated installations directories (modules, stages & installations)
rm -rf /project/g110/modules/admin-$slave/ /project/g110/spack-stages/$slave /project/g110/spack-install/$slave
Once this is done, you can use the config.py of the spack-mch instance to create the two mch instances (admin for the official installation under /project/g110/spack-install, users installation under /scratch/$user/spack/spack-install)
git clone https://github.com/MeteoSwiss-APN/spack-mch/
cd spack-mch
./config.py -m admin-$slave -i /project/g110/spack/user/admin-$slave
./config.py -m $slave -i /project/g110/spack/user/$slave
Finally install something with both instances to create a database file for the admin-instance respectively a junit-report file for the users instance, both files being needed to be able to source and install as a non-jenkins user. In order to do that first source the corresponding instances and then install something (Ex: the grib-api definitions).
Admin instance:
. /project/g110/spack/user/admin-$slave/spack/share/spack/setup-env.sh
spack install cosmo-grib-api-definition
Users instance:
. /project/g110/spack/user/admin-$slave/spack/share/spack/setup-env.sh
spack install cosmo-grib-api-definition