diff --git a/dedal/spack_factory/SpackOperationUseCache.py b/dedal/spack_factory/SpackOperationUseCache.py
index 1105a6e43e32f24d056433fdb138a442aabdcb5f..6575ba99a9fc20011031b2109f6b6e87b1232680 100644
--- a/dedal/spack_factory/SpackOperationUseCache.py
+++ b/dedal/spack_factory/SpackOperationUseCache.py
@@ -26,11 +26,15 @@ class SpackOperationUseCache(SpackOperation):
                                              os.environ.get('BUILDCACHE_OCI_PASSWORD'),
                                              cache_version=cache_version_build)
 
-    def setup_spack_env(self):
-        """Sets up the Spack environment using cached data.
+    def setup_spack_env(self) -> None:
+        """Set up the spack environment for using the cache.
 
-        Downloads the build cache, trusts the cached public key (if available),
-        and adds the build cache as a local mirror.
+        Downloads the build cache, adds the public key to trusted keys,
+        and adds the build cache mirror.
+
+        Raises:
+            ValueError: If there is an issue with the build cache setup.
+            NoSpackEnvironmentException: If the spack environment is not set up.
         """
         super().setup_spack_env()
         try: