Surfaced by GCS team. The Cloud Storage library must stringify metadata sent in bucket and blob. Here's a known issue from not doing so: ```python from google.cloud import storage client = storage.Client(project="my-project") my_bucket = client.get_bucket("my-bucket") my_blob = my_bucket.get_blob("my-blob") my_blob.metadata["bad"] = float('nan') my_blob.patch() ``` `myblob.patch()` will send an unquoted `NaN`, which is a bug in the Cloud Storage API that the client should no longer depend on.