diff --git a/packages/build-brainscales/package.py b/packages/build-brainscales/package.py
index 6ea4a3706b226418dc17b2b19ac81dbedada5887..cec40a9ca528974aa4797db930d4e05d25c55516 100644
--- a/packages/build-brainscales/package.py
+++ b/packages/build-brainscales/package.py
@@ -15,6 +15,13 @@ import spack.build_environment
 class BuildBrainscales(WafPackage):
     """Common stuff for BrainScaleS packages..."""
 
+    version(
+        "9.0-a9",
+        git="https://github.com/electronicvisions/releases-ebrains",
+        tag="ebrains-9.0-a9",
+        commit="5951428b7598ff9478fa834d7e991e3ff94709ee",
+        submodules=True,
+    )
     version(
         "9.0-a8",
         git="https://github.com/electronicvisions/releases-ebrains",
@@ -52,6 +59,7 @@ class BuildBrainscales(WafPackage):
     )
 
     # common dependencies of BuildBrainscales-derived packages
+    depends_on('oppulance@9.0-a9', when='@9.0-a9', type=('build', 'link', 'run', 'test'))
     depends_on('oppulance@9.0-a8', when='@9.0-a8', type=('build', 'link', 'run', 'test'))
     depends_on('oppulance@9.0-a7', when='@9.0-a7', type=('build', 'link', 'run', 'test'))
     depends_on('oppulance@9.0-a6', when='@9.0-a6', type=('build', 'link', 'run', 'test'))
diff --git a/packages/hxtorch/package.py b/packages/hxtorch/package.py
index 437a6886d10b56de559226fe12eeab475b87d8f3..ef237cebb64422dee0bd0989ef871c0b0a1dd5e1 100644
--- a/packages/hxtorch/package.py
+++ b/packages/hxtorch/package.py
@@ -90,6 +90,9 @@ class Hxtorch(build_brainscales.BuildBrainscales):
 
     extends('python')
 
+    # some versions of dependencies are broken
+    conflicts("boost@1.86.0") # sha1 digest changed length, but boost::compute didn't adapt
+
     patch("include-SparseTensorUtils.patch", when="@:8.0-a5")
 
     def install_test(self):
diff --git a/packages/oppulance/package.py b/packages/oppulance/package.py
index 2249a8b49fcd95084214f53a4af45fcebb1c5302..55d6b04e8c209298ff37fd1e38bef9dc917f7ddf 100644
--- a/packages/oppulance/package.py
+++ b/packages/oppulance/package.py
@@ -21,6 +21,13 @@ class Oppulance(Package):
     depends_on('wget')
     depends_on('gmp')
 
+    version(
+        "9.0-a9",
+        git="https://github.com/electronicvisions/releases-ebrains",
+        tag="ebrains-9.0-a9",
+        commit="5951428b7598ff9478fa834d7e991e3ff94709ee",
+        submodules=True,
+    )
     version(
         "9.0-a8",
         git="https://github.com/electronicvisions/releases-ebrains",
diff --git a/packages/pynn-brainscales/package.py b/packages/pynn-brainscales/package.py
index 13d850f743803aef5553cb166bd3419c8f193e2f..3e68558dfe5f3a9b9974b69737b3727906b28152 100644
--- a/packages/pynn-brainscales/package.py
+++ b/packages/pynn-brainscales/package.py
@@ -82,6 +82,9 @@ class PynnBrainscales(build_brainscales.BuildBrainscales):
     depends_on('yaml-cpp+shared', type=('build', 'link', 'run'))
     extends('python')
 
+    # some versions of dependencies are broken
+    conflicts("boost@1.86.0") # sha1 digest changed length, but boost::compute didn't adapt
+
     def install_test(self):
         with working_dir('spack-test', create=True):
             old_pythonpath = os.environ.get('PYTHONPATH', '')
diff --git a/packages/wf-brainscales2-demos/package.py b/packages/wf-brainscales2-demos/package.py
index 9226c76a37defcb3c8317e9eccba93dfbc0aca7f..1dc5b24b44c99dcf6d34e1fe7b28052d17dc5d8c 100644
--- a/packages/wf-brainscales2-demos/package.py
+++ b/packages/wf-brainscales2-demos/package.py
@@ -16,6 +16,7 @@ class WfBrainscales2Demos(Package):
     maintainers = ["emuller", "muffgaga"]
 
     # ECM: we probably should build the ipynb file in this package
+    version("9.0-a9", tag="jupyter-notebooks-9.0-a9")
     version("9.0-a8", tag="jupyter-notebooks-9.0-a8")
     version("9.0-a7", tag="jupyter-notebooks-9.0-a7")
     version("9.0-a6", tag="jupyter-notebooks-9.0-a6")
diff --git a/spack.yaml b/spack.yaml
index 274a55d1459a82d6ef6142560e30018141531416..c6d455fd5367bfb0b8999ff6348050a81cd83897 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -12,10 +12,10 @@ spack:
     - py-biobb-model@4.1.0
     - py-biobb-structure-checking@3.13.4
     - py-biobb-structure-utils@4.1.0
-    - hxtorch@9.0-a8
+    - hxtorch@9.0-a9
     - nest@3.8 +sonata
     - neuron@8.2.3 +mpi
-    - jaxsnn@9.0-a8
+    - jaxsnn@9.0-a9
     - py-bluepyefe@2.3.6
     - py-bluepymm@0.8.7
     - py-bluepyopt@1.14.11
@@ -62,14 +62,14 @@ spack:
     - py-tvb-ext-xircuits@1.1.0
     - py-viziphant@0.4.0
     - py-vbi
-    - pynn-brainscales@9.0-a8
+    - pynn-brainscales@9.0-a9
     - r-rgsl@0.1.1
     - r-sbtabvfgen@0.1
     - r-uqsa@2.2
     - sda@7.3.3d
     # Workflows (meta-packages)
     - wf-biobb
-    - wf-brainscales2-demos@9.0-a8
+    - wf-brainscales2-demos@9.0-a9
     - wf-bsb@4.4 +nest +neuron
     - wf-protein-association-rates@0.1
     - wf-multi-area-model@1.2.0