Logs: array attribute values are silently dropped (and diverge from sentry-javascript)

Bắt đầu trong sentry_sdk/utils.py tại format_attribute, khoảng dòng 2125, và theo dõi cách các thuộc tính của logger được serialize trước khi ingestion. So sánh hành vi của Python với hành vi fallback được mô tả của @sentry/core serializeAttributes. Được xem là hoàn thành khi các giá trị không nguyên thủy không còn biến mất một cách im lặng và hành vi serialize hoặc chẩn đoán đã chọn được bao phủ bởi các kiểm tra hiện có liên quan.

Environment

sentry-sdk 2.61.0, Python 3.14, logs enabled via enable_logs=True.

What happened

Passing a list-valued attribute to sentry_sdk.logger.* results in the attribute silently disappearing from the Logs UI — no value, no warning, no debug log.

sentry_sdk.logger.info(
    "workflow_engine processed event",
    attributes={
        "workflow_ids": [101, 202, 303],   # list[int]  -> dropped (blank in UI)
        "rule_names": ["high_cpu", "oom"],  # list[str]  -> dropped (blank in UI)
        "organization_id": 42,              # int        -> stored OK
        "mixed_list": [1, "two", 3.0],      # mixed      -> stored as the string "[1, 'two', 3.0]"
        "nested_dict": {"a": [1, 2]},       # dict       -> stored as the string "{'a': [1, 2]}"
    },
)

Querying the log back (EAP logs dataset), the homogeneous scalar lists come back null, while the scalars and the stringified mixed/dict values are present.

Root cause

format_attribute (sentry_sdk/utils.py:2125) preserves a homogeneous scalar list/tuple as a real array, but falls back to safe_repr (a string) for mixed lists and objects:

elif isinstance(val, list):
    ty = type(val[0])
    if ty in (str, int, float, bool) and all(type(v) is ty for v in val):
        return copy.deepcopy(val)   # sent as a real array
...
return safe_repr(val)               # everything else -> string

Sentry's log storage (EAP) only retains scalar attribute types (string / number / boolean), so the real arrays are dropped on ingestion. The net effect is counterintuitive: homogeneous lists vanish, but mixed lists/objects survive (as strings).

Divergence from sentry-javascript

@sentry/core (v10.50) does the opposite for logs — serializeAttributes(logAttributes, true) runs with fallback=true, so every non-primitive (arrays and objects) is JSON.stringify'd into a string attribute and shows up. Its attributes.js even has an explicit comment that it intentionally does not send real arrays yet to avoid a future breaking change. So the same logging API gives different results across SDKs.

Suggested fix

Make Python consistent with JS for now: stringify non-primitive attribute values (instead of sending homogeneous arrays that get dropped), or at minimum emit a debug log / drop-record when an attribute value can't be represented, so the loss isn't silent.

A docs note has been added in getsentry/sentry-docs#17921.

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