diff --git a/dedal/bll/SpackManager.py b/dedal/bll/SpackManager.py
index e5fae221c7093bff86a4adf541e4664fda353dff..075d7518f72a3f7480c0a67f365fc08e510e88ca 100644
--- a/dedal/bll/SpackManager.py
+++ b/dedal/bll/SpackManager.py
@@ -17,7 +17,7 @@ class SpackManager:
         return SpackOperationCreator.get_spack_operator(self._spack_config, self._use_cache)
 
     def install_spack(self, version: str, bashrc_path=os.path.expanduser("~/.bashrc")):
-        self._get_spack_operation().install_spack(spack_version=f'v{version}', bashrc_path=bashrc_path)
+        self._get_spack_operation().install_spack(spack_version=f'{version}', bashrc_path=bashrc_path)
 
     def add_spack_repo(self, repo: SpackDescriptor):
         """
diff --git a/dedal/build_cache/BuildCacheManager.py b/dedal/build_cache/BuildCacheManager.py
index 98fd234de0ec5282dbde338608371a09fb49d049..63b8b455775c3bbfcb7e588af1e75040c568b611 100644
--- a/dedal/build_cache/BuildCacheManager.py
+++ b/dedal/build_cache/BuildCacheManager.py
@@ -83,7 +83,7 @@ class BuildCacheManager(BuildCacheManagerInterface):
             return self._client.get_tags(self._oci_registry_path)
         except Exception as e:
             self._logger.error(f"Failed to list tags: {e}")
-        return None
+        return []
 
     def download(self, download_dir: Path):
         """
diff --git a/dedal/spack_factory/SpackOperation.py b/dedal/spack_factory/SpackOperation.py
index b0c0a78b8fd75cca7f989eb838c71f5ed574b444..ca7175721040e77429f232852b5bcb469f70251f 100644
--- a/dedal/spack_factory/SpackOperation.py
+++ b/dedal/spack_factory/SpackOperation.py
@@ -363,7 +363,7 @@ class SpackOperation:
         log_command(install_result, str(Path(os.getcwd()).resolve() / ".generate_cache.log"))
         return install_result
 
-    def install_spack(self, spack_version=f'v{SPACK_VERSION}', spack_repo='https://github.com/spack/spack',
+    def install_spack(self, spack_version=f'{SPACK_VERSION}', spack_repo='https://github.com/spack/spack',
                       bashrc_path=os.path.expanduser("~/.bashrc")):
         """Install spack.
             Args:
@@ -371,6 +371,7 @@ class SpackOperation:
                 spack_repo (str): Git path to the Spack repository.
                 bashrc_path (str): Path to the .bashrc file.
         """
+        spack_version = f'v{spack_version}'
         try:
             user = os.getlogin()
         except OSError:
diff --git a/dedal/spack_factory/SpackOperationUseCache.py b/dedal/spack_factory/SpackOperationUseCache.py
index 751945980f0fdd98923f43182ea89b2a639774f2..45c0ab4f189f8d5d35f0e2f53f84f31f64171df5 100644
--- a/dedal/spack_factory/SpackOperationUseCache.py
+++ b/dedal/spack_factory/SpackOperationUseCache.py
@@ -60,7 +60,6 @@ class SpackOperationUseCache(SpackOperation):
             NoSpackEnvironmentException: If the spack environment is not set up.
         """
         concretization_redo = False
-        self.cache_dependency.download(self.spack_config.concretization_dir)
         if file_exists_and_not_empty(self.spack_config.concretization_dir / 'spack.lock'):
             concretization_file_path = self.env_path / 'spack.lock'
             copy_file(self.spack_config.concretization_dir / 'spack.lock', self.env_path)
@@ -72,6 +71,10 @@ class SpackOperationUseCache(SpackOperation):
             # redo the concretization step if spack.lock file was not downloaded from the cache
             super().concretize_spack_env(force=True, test=test)
             concretization_redo = True
+        if concretization_redo is True:
+            self.logger.info(f'Redo of concretization step.')
+        else:
+            self.logger.info(f'USed concretization from cache.')
         return concretization_redo
 
     @check_spack_env
@@ -94,4 +97,5 @@ class SpackOperationUseCache(SpackOperation):
                                      exception_msg=f"Error installing spack packages for {self.spack_config.env.name}",
                                      exception=SpackInstallPackagesException)
         log_command(install_result, str(Path(os.getcwd()).resolve() / ".generate_cache.log"))
+        self.logger.info(f'Finished installation of spack packages from cache.')
         return install_result
diff --git a/dedal/tests/integration_tests/spack_install_test.py b/dedal/tests/integration_tests/spack_install_test.py
index 0c6cf1273cf57b5ccb82e4c4cd79fc913aebeaaf..b0e42ae0f88cbdd0fee5588058d60d0d7a6f393a 100644
--- a/dedal/tests/integration_tests/spack_install_test.py
+++ b/dedal/tests/integration_tests/spack_install_test.py
@@ -7,6 +7,7 @@ def test_spack_install_scratch(tmp_path):
     install_dir = tmp_path
     spack_config = SpackConfig(install_dir=install_dir)
     spack_operation = SpackOperation(spack_config)
-    spack_operation.install_spack(spack_version=f'v{SPACK_VERSION}')
+    spack_operation.install_spack(spack_version=f'{SPACK_VERSION}')
     installed_spack_version = spack_operation.get_spack_installed_version()
     assert SPACK_VERSION == installed_spack_version
+