diff --git a/env/merlin/spack.yaml b/env/merlin/spack.yaml
index e9a3354..97ebae8 100644
--- a/env/merlin/spack.yaml
+++ b/env/merlin/spack.yaml
@@ -542,29 +542,30 @@ spack:
         - PKG_CONFIG_PATH
 #<<<
   specs:
-    - matrix:
-      - [alps, geant4]
-      - ['%gcc@8.3.0']
-      - [^openmpi]
-      - [^openblas]
-      - [^boost@1.63.0+python+numpy cxxstd=11 +icu ^icu4c cxxstd=11 ^py-numpy@1.19.5 ^python@3.6.13]
-    - matrix:
-      - [gromacs, h5hut+mpi, lammps, vtk]
-      - ['%gcc@12.1.0']
-      - [^openmpi]
-      - [^openblas]
-# to be fixed
-#     - matrix:
-#       - [cp2k]
-#       - ['%oneapi']
-#       - [^intel-oneapi-mpi]
-#       - [^intel-oneapi-mkl]
-#     - matrix:
-#       - [relion +cuda]
-#       - ['%nvhpc']
-#       - [^openmpi]
-#       - [^openblas]
-#
+  - matrix:
+    - [alps, geant4]
+    - ['%gcc@8.3.0']
+    - [^openmpi]
+    - [^openblas]
+    - [^boost@1.63.0+python+numpy cxxstd=11 +icu ^icu4c cxxstd=11 ^py-numpy@1.19.5
+        ^python@3.6.13]
+  - matrix:
+    - [gromacs, h5hut+mpi, lammps, visit]
+    - ['%gcc@12.1.0']
+    - [^openmpi]
+    - [^openblas]
+    - [^py-numpy@1.19.5%gcc@8.3.0 ^python@3.6.13%gcc@8.3.0]
+  # to be fixed
+  #     - matrix:
+  #       - [cp2k]
+  #       - ['%oneapi']
+  #       - [^intel-oneapi-mpi]
+  #       - [^intel-oneapi-mkl]
+  #     - matrix:
+  #       - [relion +cuda]
+  #       - ['%nvhpc']
+  #       - [^openmpi]
+  #       - [^openblas]
   view:
     Batchsystem:
       link: all