microg/GmsCore · error · IllegalStateException

Must set attenuationBucketWeights

Error message

Must set attenuationBucketWeights

What it means

DailySummariesConfig.Builder.build() throws IllegalStateException when attenuationBucketWeights was never set. The config needs one weight per attenuation bucket to score each exposure day; without it the summary would be meaningless, so the builder fails fast.

Source

Thrown at play-services-nearby/src/main/java/com/google/android/gms/nearby/exposurenotification/DailySummariesConfig.java:190

     */
    public static class DailySummariesConfigBuilder {
        private Double[] reportTypeWeights = new Double[ReportType.VALUES];
        private Double[] infectiousnessWeights = new Double[Infectiousness.VALUES];
        private List<Integer> attenuationBucketThresholdDb;
        private List<Double> attenuationBucketWeights;
        private int daysSinceExposureThreshold;
        private double minimumWindowScore;

        public DailySummariesConfigBuilder() {
            Arrays.fill(reportTypeWeights, 0.0);
            Arrays.fill(infectiousnessWeights, 0.0);
        }

        public DailySummariesConfig build() {
            if (attenuationBucketThresholdDb == null)
                throw new IllegalStateException("Must set attenuationBucketThresholdDb");
            if (attenuationBucketWeights == null)
                throw new IllegalStateException("Must set attenuationBucketWeights");
            DailySummariesConfig config = new DailySummariesConfig();
            config.reportTypeWeights = Arrays.asList(reportTypeWeights);
            config.infectiousnessWeights = Arrays.asList(infectiousnessWeights);
            config.attenuationBucketThresholdDb = attenuationBucketThresholdDb;
            config.attenuationBucketWeights = attenuationBucketWeights;
            config.daysSinceExposureThreshold = daysSinceExposureThreshold;
            config.minimumWindowScore = minimumWindowScore;
            return config;
        }

        /**
         * See {@link #getAttenuationBucketThresholdDb()} and {@link #getAttenuationBucketWeights()}
         */
        public DailySummariesConfigBuilder setAttenuationBuckets(List<Integer> thresholds, List<Double> weights) {
            attenuationBucketThresholdDb = new ArrayList<>(thresholds);
            attenuationBucketWeights = new ArrayList<>(weights);
            return this;
        }

View on GitHub (pinned to 157c9d86ac)

Solutions

  1. Call builder.setAttenuationBucketWeights(...) with 4 weights (one per attenuation bucket) before build()
  2. Verify the weights list size matches the number of buckets implied by the thresholds
  3. Review the builder chain to ensure no required setter is skipped

Example fix

// before
builder.setAttenuationBucketThresholdDb(Arrays.asList(30, 40, 60));
DailySummariesConfig config = builder.build();
// after
builder.setAttenuationBucketThresholdDb(Arrays.asList(30, 40, 60));
builder.setAttenuationBucketWeights(Arrays.asList(1.0, 1.0, 1.0, 1.0));
DailySummariesConfig config = builder.build();
Defensive patterns

Strategy: validation

Validate before calling

List<Double> weights = Arrays.asList(1.0, 1.0, 1.0, 1.0);
if (weights == null || weights.size() != 4) {
    throw new IllegalStateException("attenuationBucketWeights must be set (4 values)");
}
DailySummariesConfig config = builder.setAttenuationBucketWeights(weights).build();

Try / catch

try {
    DailySummariesConfig config = builder.build();
} catch (IllegalStateException e) {
    Log.w(TAG, "Incomplete DailySummariesConfig: " + e.getMessage());
}

Prevention

When it happens

Trigger: Calling DailySummariesConfig.Builder.build() without calling setAttenuationBucketWeights(List<Double>) — only after the attenuationBucketThresholdDb check has already passed.

Common situations: Developers set thresholds but forget the matching weights list, or copy an example config that sets weights conditionally.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

AI-assisted analysis of microg/GmsCore@157c9d86ac (2026-09-06). Data as JSON: /api/errors/0752f9ec44b516eb. Report an issue: GitHub.