What causes "GitHub GraphQL returned no pages" in 666ghj/MiroFish?

If you hit this after modifying the backfill loop, restore the invariant: the first `fetch_stargazer_page` result must set `initial_total` and `pages_required` before any `continue`/`break`.

666ghj/MiroFish · error · StarHistoryError

GitHub GraphQL returned no pages

Error message

GitHub GraphQL returned no pages

What it means

Raised at scripts/star_history.py:607 immediately after the backfill pagination loop: if `initial_total` is still None, the `while True` loop never completed even one `github.fetch_stargazer_page()` call that reached the total-count assignment. It is a defensive assertion that should be unreachable in practice (the loop always executes at least once or raises earlier), guarding against control-flow regressions.

Source

Thrown at scripts/star_history.py:607

                raise StarHistoryError("GitHub GraphQL repeated an edge cursor")
            seen_edge_cursors.add(edge.cursor)
            if edge.starred_at.date() < normalized_now.date():
                daily_increments[edge.starred_at.date()] += 1

        if page.end_cursor is not None:
            if page.end_cursor in seen_page_cursors:
                raise StarHistoryError("GitHub GraphQL repeated a page cursor")
            seen_page_cursors.add(page.end_cursor)
        if not page.has_next_page:
            break
        if page.end_cursor is None:
            raise StarHistoryError("GitHub GraphQL omitted the next page cursor")
        after = page.end_cursor
        if page_number > 10_000:
            raise StarHistoryError("GitHub GraphQL exceeded the page safety limit")

    if initial_total is None:
        raise StarHistoryError("GitHub GraphQL returned no pages")
    if len(seen_edge_cursors) != initial_total:
        raise StarHistoryError("stargazer list changed or was incomplete during backfill")

    running = 0
    daily: list[dict[str, Any]] = []
    for point_day in sorted(daily_increments):
        running += daily_increments[point_day]
        daily.append({"date": point_day.isoformat(), "stars": running})

    state: dict[str, Any] = {
        "schema_version": 1,
        "repository": REPOSITORY,
        "timezone": "UTC",
        "ongoing_interval_days": INTERVAL_DAYS,
        "reconstruction": {
            "method": "current_stargazers_starred_at",
            "generated_at": _format_state_timestamp(normalized_now),
            "daily": daily,

View on GitHub (pinned to b5b53acc57)

Solutions

If you hit this after modifying the backfill loop, restore the invariant: the first `fetch_stargazer_page` result must set `initial_total` and `pages_required` before any `continue`/`break`.
Run the repository's test suite for scripts/star_history.py — this assertion exists to make loop refactorings fail loudly.
If untouched code raises it, report a control-flow bug; include the traceback showing how the loop exited without an exception.

Defensive patterns

Strategy: try-catch

Try / catch

try:
    state = run_backfill(gateway, clock)
except StarHistoryError as exc:
    if "returned no pages" in str(exc):
        raise RuntimeError("control-flow bug in backfill loop; report upstream") from exc
    raise

Prevention

Do not refactor the backfill loop without running its full test suite — this assertion exists to catch structural regressions.
Keep the initial_total assignment unconditional on the first page fetch if you must restructure the loop.
Never wrap fetch_stargazer_page in an exception swallower that could let the loop `continue` past the assignment.

When it happens

Trigger: Structurally unreachable via the public API: the loop body unconditionally sets `initial_total = page.total_count` on the first iteration, and every exit path from the loop either goes through `break` (after ≥1 page) or raises a different StarHistoryError. Only a refactoring bug (e.g. a future `continue` before the assignment, or an exception-swallowing wrapper) can leave `initial_total` None at line 607.

Common situations: Essentially never seen in production; appears only when someone edits the loop structure (moving the `initial_total` assignment behind a condition) or in mutant/coverage tests that exercise the dead branch.

Related errors

AI-assisted analysis of 666ghj/MiroFish@b5b53acc57 (2026-08-14). Data as JSON: /api/errors/37b2b6881357d203. Report an issue: GitHub.