tursodatabase/turso · error · ValueError

no sweep results found

Error message

no sweep results found

What it means

read_sweep raises this ValueError when the provided path list is empty or yielded no parseable sweep points, meaning there is nothing to plot. It is the guard against silently producing an empty connection-sweep chart.

Solutions

  1. Pass at least one valid sweep result CSV to plot-fts.py.
  2. Check the results directory/glob actually contains sweep files.
  3. Generate sweep results by running the FTS benchmark before plotting.

Example fix

# before
python plot-fts.py results/empty-dir/*.csv
# after
python plot-fts.py results/c1.csv results/c8.csv
Defensive patterns

Strategy: validation

Validate before calling

import glob
paths = sorted(glob.glob('results/sweep-*.csv'))
assert paths, 'no sweep result files found; run the benchmark first'

Try / catch

try:
    config, points = read_sweep(paths)
except ValueError as e:
    if 'no sweep results found' in str(e):
        print('Fix: point plot-fts.py at existing sweep CSV files')
    else:
        raise

Prevention

When it happens

Trigger: Calling read_sweep (via main) with an empty list of sweep CSV paths, or paths whose read_runs calls raised/excluded all points such that `points` stays empty.

Common situations: Running plot-fts.py against an empty results directory or a glob that matched nothing; all candidate files were rejected earlier in the pipeline.

Understand the failure class

Background: EmptyResultError / "no results found": when an API or scraper succeeds but returns zero rows — this error's family across 9 libraries.

Related errors

AI-assisted analysis of tursodatabase/turso@8d4a589f8d (2026-09-20). Data as JSON: /api/errors/a421018f6d09619b. Report an issue: GitHub.

Appendix: source

Thrown at perf/fts/plot/plot-fts.py:64

            plot(configuration, samples, output)
        print(f"wrote {output}")


def read_sweep(paths, percentile="p50"):
    configuration = None
    points = {}
    for path in paths:
        current, samples = read_runs([path], percentile)
        connections = int(current.pop("connections"))
        if connections <= 0 or connections in points:
            raise ValueError("each sweep file must have a distinct positive connection count")
        if configuration is None:
            configuration = current
        if current != configuration or (points and set(samples) != set(next(iter(points.values())))):
            raise ValueError("sweep files must match benchmark, sample budget, fixture and engine/mode series")
        points[connections] = samples
    if not points:
        raise ValueError("no sweep results found")
    return configuration, dict(sorted(points.items()))


def read_runs(paths, percentile="p50"):
    configuration = None
    samples = {}
    expected_series = None
    for path in paths:
        current, runs = read_file(path, percentile, samples)
        if configuration is None:
            configuration = current
        if configuration != current:
            raise ValueError("plot only one configuration at a time")
        for run in runs.values():
            if expected_series is None:
                expected_series = set(run)
            if set(run) != expected_series or any(seen != set(QUERIES) for seen in run.values()):
                raise ValueError(f"{path}: each run must contain the same series and all six query cases")

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