diff --git a/env/rhel7/x86_64/sysconfigs/packages.yaml b/env/rhel7/x86_64/sysconfigs/packages.yaml
index f97042d..4b5348c 100644
--- a/env/rhel7/x86_64/sysconfigs/packages.yaml
+++ b/env/rhel7/x86_64/sysconfigs/packages.yaml
@@ -1,7 +1,7 @@
 ---
 packages:
   all:
-    compiler: [gcc@4.8.5, nvhpc]
+    compiler: [gcc@=12.3.0, gcc@4.8.5, nvhpc]
     providers:
       blas: [openblas, nvhpc]
       lapack: [openblas, nvhpc]
@@ -169,7 +169,7 @@ packages:
     buildable: false
     externals:
       - prefix: /usr
-        spec: slurm@23-11-0-1 +pmix +hwloc +hdf5 +mariadb +pam
+        spec: slurm@23-11-0-1 pmi-interface=pmi2 +hwloc +hdf5 +mariadb +pam
   sqlite:
     require: '%gcc@4.8.5'
   subversion:
diff --git a/env/rhel7/x86_64/users/stable/spack.yaml b/env/rhel7/x86_64/users/stable/spack.yaml
index d464192..572f855 100644
--- a/env/rhel7/x86_64/users/stable/spack.yaml
+++ b/env/rhel7/x86_64/users/stable/spack.yaml
@@ -7,11 +7,10 @@ spack:
       - $spack/user/$user/spack-stage
     install_tree:
       root: $spack/user/$user/spack-install
-    upstreams:
-      spack-instance-1:
-        install_tree: $spack/opt/spack/stable
-    include:
-    - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
-    - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
-    specs:
+  mirrors:
+    local_stable: file:///afs/psi.ch/software/spack/stable
+  include:
+  - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
+  - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
+  specs: []
   view: false
diff --git a/env/rhel7/x86_64/users/unstable/spack.yaml b/env/rhel7/x86_64/users/unstable/spack.yaml
index 62b3bd1..ad6a306 100644
--- a/env/rhel7/x86_64/users/unstable/spack.yaml
+++ b/env/rhel7/x86_64/users/unstable/spack.yaml
@@ -7,13 +7,10 @@ spack:
       - $spack/user/$user/spack-stage
     install_tree:
       root: $spack/user/$user/spack-install
-    upstreams:
-      spack-instance-1:
-        install_tree: $spack/opt/spack/stable
-      spack-instance-2:
-        install_tree: $spack/opt/spack/unstable
-    include:
-    - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
-    - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
-    specs:
+  mirrors:
+    local_unstable: file:///afs/psi.ch/software/spack/unstable
+  include:
+  - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
+  - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
+  specs: []
   view: false
diff --git a/env/sles15/x86_64/admin/stable/spack.yaml b/env/sles15/x86_64/admin/stable/spack.yaml
index bc62a7b..a40e24c 100644
--- a/env/sles15/x86_64/admin/stable/spack.yaml
+++ b/env/sles15/x86_64/admin/stable/spack.yaml
@@ -8,13 +8,10 @@ spack:
       - $spack/user/$user/spack-stage
     install_tree:
       root: $spack/opt/spack/stable
-  include_concrete:
-    - $spack/spack-psi/env/$os/$target_family/admin/unstable
   include:
     - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
     - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
   mirrors:
     local_stable: file:///afs/psi.ch/software/spack/stable
-    local_unstable: file:///afs/psi.ch/software/spack/unstable
   specs: []
   view: false
diff --git a/env/sles15/x86_64/admin/testing/spack.yaml b/env/sles15/x86_64/admin/testing/spack.yaml
index 8296dca..6904c8d 100644
--- a/env/sles15/x86_64/admin/testing/spack.yaml
+++ b/env/sles15/x86_64/admin/testing/spack.yaml
@@ -7,17 +7,12 @@ spack:
       - $spack/user/$user/spack-stage
     install_tree:
       root: $spack/opt/spack/testing
-  upstreams:
-    spack-instance-1:
-      install_tree: $spack/opt/spack/stable
-    spack-instance-2:
-      install_tree: $spack/opt/spack/unstable
   include:
   - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
   - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
   mirrors:
-    local_unstable: file:///afs/psi.ch/software/spack/unstable
     local_testing: file:///afs/psi.ch/software/spack/testing
+    local_unstable: file:///afs/psi.ch/software/spack/unstable
   specs:
     - cp2k@2024.1%gcc~cuda
     - opal@master%gcc
diff --git a/env/sles15/x86_64/admin/unstable/spack.yaml b/env/sles15/x86_64/admin/unstable/spack.yaml
index 97205ba..e3126a6 100644
--- a/env/sles15/x86_64/admin/unstable/spack.yaml
+++ b/env/sles15/x86_64/admin/unstable/spack.yaml
@@ -7,15 +7,11 @@ spack:
       - $spack/user/$user/spack-stage
     install_tree:
       root: $spack/opt/spack/unstable
-  upstreams:
-    spack-instance-1:
-      install_tree: $spack/opt/spack/stable
   include:
   - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
   - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
   mirrors:
-    local_stable: file:///afs/psi.ch/software/spack/stable
     local_unstable: file:///afs/psi.ch/software/spack/unstable
-    local_testing: file:///afs/psi.ch/software/spack/testing
+    local_stable: file:///afs/psi.ch/software/spack/stable
   specs: []
   view: false
diff --git a/env/sles15/x86_64/users/stable/spack.yaml b/env/sles15/x86_64/users/stable/spack.yaml
index d464192..16e3fd0 100644
--- a/env/sles15/x86_64/users/stable/spack.yaml
+++ b/env/sles15/x86_64/users/stable/spack.yaml
@@ -7,11 +7,10 @@ spack:
       - $spack/user/$user/spack-stage
     install_tree:
       root: $spack/user/$user/spack-install
-    upstreams:
-      spack-instance-1:
-        install_tree: $spack/opt/spack/stable
-    include:
+  include:
     - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
     - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
-    specs:
+  mirrors:
+    local_stable: file:///afs/psi.ch/software/spack/stable
+  specs: []
   view: false
diff --git a/env/sles15/x86_64/users/unstable/spack.yaml b/env/sles15/x86_64/users/unstable/spack.yaml
index 62b3bd1..302ffd9 100644
--- a/env/sles15/x86_64/users/unstable/spack.yaml
+++ b/env/sles15/x86_64/users/unstable/spack.yaml
@@ -7,13 +7,10 @@ spack:
       - $spack/user/$user/spack-stage
     install_tree:
       root: $spack/user/$user/spack-install
-    upstreams:
-      spack-instance-1:
-        install_tree: $spack/opt/spack/stable
-      spack-instance-2:
-        install_tree: $spack/opt/spack/unstable
-    include:
-    - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
-    - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
-    specs:
+  include:
+  - $spack/spack-psi/env/$os/$target_family/sysconfigs/packages.yaml
+  - $spack/spack-psi/env/$os/$target_family/sysconfigs/compilers.yaml
+  mirrors:
+    local_unstable: file:///afs/psi.ch/software/spack/unstable
+  specs: []
   view: false