diff --git a/rust2rpm/metadata.py b/rust2rpm/metadata.py
index 35a0416..073fa64 100644
--- a/rust2rpm/metadata.py
+++ b/rust2rpm/metadata.py
@@ -386,7 +386,13 @@ class Metadata:
             ["cargo", "read-manifest", f"--manifest-path={path}"],
             check=check, capture_output=True
         )
-        return json.loads(output.stdout)
+        try:
+            result = json.loads(output.stdout)
+        except json.decoder.JSONDecodeError:
+            # Pure virtual manifest cannot be readed, we need to use
+            # one from the different workspaces
+            result = {}
+        return result
 
     @staticmethod
     def metadata(path, deps=False):