diff --git a/.ci/asic_create_recipe.sh b/.ci/asic_create_recipe.sh
index e658b337e828fe1b10a682908b5175e78e8122ae..665907f515972a503fa7ab660f76259b5bec6a66 100755
--- a/.ci/asic_create_recipe.sh
+++ b/.ci/asic_create_recipe.sh
@@ -35,7 +35,6 @@ From: ${DOCKER_BASE_IMAGE}
     mkdir "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     rsync -av "${SOURCE_DIR}"/*.sh "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     rsync -av "${SOURCE_DIR}"/*.awk "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
-    rsync -av "${SOURCE_DIR}"/pinned "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     rsync -av "${SOURCE_DIR}"/patches "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     mkdir -p "\${SINGULARITY_ROOTFS}/${META_DIR_INSIDE}"
     rsync -av "${META_DIR_OUTSIDE}"/* "\${SINGULARITY_ROOTFS}/${META_DIR_INSIDE}"
diff --git a/.ci/commons.sh b/.ci/commons.sh
index 7c1a66e7d480a7eecbcc398373527399b2049611..da230357931451cbd5aaf02bf6443e2adc060874 100755
--- a/.ci/commons.sh
+++ b/.ci/commons.sh
@@ -169,39 +169,8 @@ fi
 # PACKAGES #
 ############
 
-# Usage: get_pinned_deps <name>
-#
-# Note: This pinning is used only to help the concretizer make suitable picks.
-# The actual incompatabilities should still be expressed in the spack packages.
-#
-# The real reason for this machinery is the fact that the concretizer, despite
-# specifying which version of the package is compatible with python 2 and 3, is
-# unable to determine the last version still compatible with python 2
-#
-# Arguments:
-#   <name> has to correspond to a list of pinned dependencies residing under
-#   <yashchiki-root>/container-build-files/pinned/<name>.list
-#   The file should contain a list of spec constraints (one spec per line).
-#   Lines starting with and everything followed by # will be considered
-#   comments and removed.
-get_pinned_deps() {
-    local depsname="${1}"
-    local filename="${COMMONS_DIR}/pinned/${depsname}.list"
-
-    if [ ! -f "${filename}" ]; then
-        echo "ERROR: No dependencies for ${depsname} found at ${filename}!" >&2
-        exit 1
-    fi
-    # The grep call removes lines starting with # as well as blank lines. sed
-    # then removes trailing comments. Afterwards we insert a tilde (^) in front
-    # of every line (i.e., dependency) and join all lines by replacing the
-    # newline character with spaces.
-    grep -v "\(^#\|^\s*$\)" "${filename}" | sed -e "s:#.*$::" \
-        | sed -e "s:^:\^:" | tr '\n' ' '
-}
-
 # the version of dev tools we want in our view
-SPEC_VIEW_VISIONARY_DEV_TOOLS="visionary-dev-tools ^${DEPENDENCY_PYTHON3} $(get_pinned_deps dev) %${YASHCHIKI_SPACK_GCC}"
+SPEC_VIEW_VISIONARY_DEV_TOOLS="visionary-dev-tools ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
 
 # used in VIEWS section below but needs to be defined before sourcing
 # associative array: spec to add -> view names seperated by spaces
diff --git a/.ci/install_spack.sh b/.ci/install_spack.sh
index 42b4ec9bc453d86d5ce59007d652c555cffe84bf..974943f56f8e833aea93e0dcf4922add1469e60b 100755
--- a/.ci/install_spack.sh
+++ b/.ci/install_spack.sh
@@ -13,6 +13,14 @@ cd "$HOME"
 
 install_from_buildcache "${spack_packages[@]+"${spack_packages[@]}"}"
 
+echo "DUMMY-INSTALLING PACKAGES"
+for package in "${spack_packages[@]+"${spack_packages[@]}"}"; do
+    specfile="$(get_specfiles "${package}")"
+    if (( $(wc -l <"${specfile}") == 0 )); then
+        echo "ERROR: Failed to concretize ${package} for install." >&2
+    fi
+done
+
 echo "INSTALLING PACKAGES"
 for package in "${spack_packages[@]+"${spack_packages[@]}"}"; do
     # Disable cache because we already installed from build cache.
diff --git a/.ci/visionary_create_recipe.sh b/.ci/visionary_create_recipe.sh
index d01033f76fda0a41afdbd5d00ec5ca6d736eacea..7f6422f64dc1068e39171219b5bb147de50d13fd 100755
--- a/.ci/visionary_create_recipe.sh
+++ b/.ci/visionary_create_recipe.sh
@@ -40,7 +40,6 @@ From: ${DOCKER_BASE_IMAGE}
     mkdir "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     rsync -av "${SOURCE_DIR}"/*.sh "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     rsync -av "${SOURCE_DIR}"/*.awk "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
-    rsync -av "${SOURCE_DIR}"/pinned "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     rsync -av "${SOURCE_DIR}"/patches "\${SINGULARITY_ROOTFS}/${SPACK_INSTALL_SCRIPTS}"
     mkdir -p "\${SINGULARITY_ROOTFS}/${META_DIR_INSIDE}"
     rsync -av "${META_DIR_OUTSIDE}"/* "\${SINGULARITY_ROOTFS}/${META_DIR_INSIDE}"
@@ -138,10 +137,4 @@ for view in "${spack_views[@]}"; do
         generate_appenv "${view}" "${view}"
         [[ "${view}" =~ ^visionary- ]] && generate_appenv "${view#visionary-}" "${view}"
     ) >> "${RECIPE_FILENAME}"
-
-    if [ "${view}" = "visionary-simulation" ];then
-cat <<EOF >>"${RECIPE_FILENAME}"
-    export NEST_MODULES=visionarymodule
-EOF
-    fi
 done
diff --git a/.ci/visionary_spack_collection.sh b/.ci/visionary_spack_collection.sh
index 9275c2d246c4674d880fccc5050fac69c5642ea9..c86dd4b7e547e4bae2b6d0519843d66bd6887ed9 100644
--- a/.ci/visionary_spack_collection.sh
+++ b/.ci/visionary_spack_collection.sh
@@ -1,17 +1,15 @@
 # All spack packages that should be fetched/installed in the container
 spack_packages=(
     "${SPEC_VIEW_VISIONARY_DEV_TOOLS}"
-    "visionary-simulation~dev ^${DEPENDENCY_PYTHON} $(get_pinned_deps simulation) %${YASHCHIKI_SPACK_GCC}"
-    "visionary-simulation ^${DEPENDENCY_PYTHON} $(get_pinned_deps simulation) %${YASHCHIKI_SPACK_GCC}"
     # START python 3 packages
-    "visionary-wafer~dev ^${DEPENDENCY_PYTHON3} $(get_pinned_deps wafer) %${YASHCHIKI_SPACK_GCC}"
-    "visionary-wafer ^${DEPENDENCY_PYTHON3} $(get_pinned_deps wafer) %${YASHCHIKI_SPACK_GCC}"
-    "visionary-wafer~dev+gccxml ^${DEPENDENCY_PYTHON3} $(get_pinned_deps wafer) %${YASHCHIKI_SPACK_GCC}"
-    "visionary-wafer+gccxml ^${DEPENDENCY_PYTHON3} $(get_pinned_deps wafer) %${YASHCHIKI_SPACK_GCC}"
-    "visionary-wafer-visu ^${DEPENDENCY_PYTHON3} $(get_pinned_deps wafer-visu) %${YASHCHIKI_SPACK_GCC}"
+    "visionary-wafer~dev ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
+    "visionary-wafer ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
+    "visionary-wafer~dev+gccxml ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
+    "visionary-wafer+gccxml ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
+    "visionary-wafer-visu ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
     "visionary-clusterservices ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
-    "visionary-dls~dev ^${DEPENDENCY_PYTHON3} $(get_pinned_deps dls) %${YASHCHIKI_SPACK_GCC}"
-    "visionary-dls ^${DEPENDENCY_PYTHON3} $(get_pinned_deps dls) %${YASHCHIKI_SPACK_GCC}"
+    "visionary-dls~dev ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
+    "visionary-dls ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
     "py-jupyterhub ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
     "py-jupyterhub-dummyauthenticator ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
     "py-jupyterhub-simplespawner ^${DEPENDENCY_PYTHON3} %${YASHCHIKI_SPACK_GCC}"
@@ -23,8 +21,6 @@ spack_views=(\
     visionary-dls-core
     visionary-dls
     visionary-dls-nodev
-    visionary-simulation
-    visionary-simulation-nodev
     visionary-slurmviz
     visionary-wafer
     visionary-wafer-nodev
diff --git a/.ci/visionary_spack_custom_view.sh b/.ci/visionary_spack_custom_view.sh
index 22be6163073e112f64ec46972fe354060bd56802..947f8e07cb3778c12299e1d0a1dae718c1b63a43 100644
--- a/.ci/visionary_spack_custom_view.sh
+++ b/.ci/visionary_spack_custom_view.sh
@@ -10,9 +10,6 @@ ${MY_SPACK_BIN} ${SPACK_ARGS_VIEW[@]+"${SPACK_ARGS_VIEW[@]}"} view -d yes symlin
 # Strong independent packages who need no gccxml #
 ##################################################
 
-${MY_SPACK_BIN} ${SPACK_ARGS_VIEW[@]+"${SPACK_ARGS_VIEW[@]}"} view -d yes symlink -i ${MY_SPACK_VIEW_PREFIX}/visionary-simulation $(get_latest_hash "visionary-simulation+dev")
-${MY_SPACK_BIN} ${SPACK_ARGS_VIEW[@]+"${SPACK_ARGS_VIEW[@]}"} view -d yes symlink -i ${MY_SPACK_VIEW_PREFIX}/visionary-simulation-nodev $(get_latest_hash "visionary-simulation~dev")
-
 ${MY_SPACK_BIN} ${SPACK_ARGS_VIEW[@]+"${SPACK_ARGS_VIEW[@]}"} view -d yes symlink -i ${MY_SPACK_VIEW_PREFIX}/visionary-dls-core $(get_latest_hash visionary-dls-core "^${DEPENDENCY_PYTHON3}")
 
 ${MY_SPACK_BIN} ${SPACK_ARGS_VIEW[@]+"${SPACK_ARGS_VIEW[@]}"} view -d yes symlink -i ${MY_SPACK_VIEW_PREFIX}/visionary-dls $(get_latest_hash visionary-dls+dev "^${DEPENDENCY_PYTHON3}")