microg/GmsCore · error · IllegalStateException

Must set reportTypeWhenMissing

Error message

Must set reportTypeWhenMissing

What it means

DiagnosisKeysDataMapping.Builder.build() throws IllegalStateException when reportTypeWhenMissing is still ReportType.UNKNOWN (its default). The API needs to know which report type to assume when a key has no report type; UNKNOWN is treated as 'not configured'.

Source

Thrown at play-services-nearby/src/main/java/com/google/android/gms/nearby/exposurenotification/DiagnosisKeysDataMapping.java:82

        return reportTypeWhenMissing;
    }

    /**
     * A builder for {@link DiagnosisKeysDataMapping}.
     */
    public static class DiagnosisKeysDataMappingBuilder {
        private final static int MAX_DAYS = 29;
        private List<Integer> daysSinceOnsetToInfectiousness;
        @ReportType
        private int reportTypeWhenMissing = ReportType.UNKNOWN;
        @Infectiousness
        private Integer infectiousnessWhenDaysSinceOnsetMissing;

        public DiagnosisKeysDataMapping build() {
            if (daysSinceOnsetToInfectiousness == null)
                throw new IllegalStateException("Must set daysSinceOnsetToInfectiousness");
            if (reportTypeWhenMissing == ReportType.UNKNOWN)
                throw new IllegalStateException("Must set reportTypeWhenMissing");
            if (infectiousnessWhenDaysSinceOnsetMissing == null)
                throw new IllegalStateException("Must set infectiousnessWhenDaysSinceOnsetMissing");
            DiagnosisKeysDataMapping mapping = new DiagnosisKeysDataMapping();
            mapping.daysSinceOnsetToInfectiousness = new ArrayList<>(daysSinceOnsetToInfectiousness);
            mapping.reportTypeWhenMissing = reportTypeWhenMissing;
            mapping.infectiousnessWhenDaysSinceOnsetMissing = infectiousnessWhenDaysSinceOnsetMissing;
            return mapping;
        }

        public DiagnosisKeysDataMappingBuilder setDaysSinceOnsetToInfectiousness(Map<Integer, Integer> daysSinceOnsetToInfectiousness) {
            if (daysSinceOnsetToInfectiousness.size() > MAX_DAYS)
                throw new IllegalArgumentException("daysSinceOnsetToInfectiousness exceeds " + MAX_DAYS + " days");
            Integer[] values = new Integer[MAX_DAYS];
            Arrays.fill(values, 0);
            for (Map.Entry<Integer, Integer> entry : daysSinceOnsetToInfectiousness.entrySet()) {
                if (entry.getKey() > 14) throw new IllegalArgumentException("invalid day since onset");
                values[entry.getKey() + 14] = entry.getValue();
            }

View on GitHub (pinned to 157c9d86ac)

Solutions

  1. Call setReportTypeWhenMissing with a concrete type such as ReportType.CONFIRMED_TEST or ReportType.CONFIRMED_CLINICAL_DIAGNOSIS
  2. Do not pass ReportType.UNKNOWN; it is only the sentinel default
  3. Set all three required fields (map, reportTypeWhenMissing, infectiousnessWhenDaysSinceOnsetMissing) together

Example fix

// before
builder.setReportTypeWhenMissing(ReportType.UNKNOWN);
// after
builder.setReportTypeWhenMissing(ReportType.CONFIRMED_TEST);
Defensive patterns

Strategy: validation

Validate before calling

if (reportTypeWhenMissing == ReportType.UNKNOWN) {
    reportTypeWhenMissing = ReportType.CONFIRMED_TEST; // sensible default
}
builder.setReportTypeWhenMissing(reportTypeWhenMissing);

Try / catch

try {
    DiagnosisKeysDataMapping mapping = mappingBuilder.build();
} catch (IllegalStateException e) {
    Log.w(TAG, "reportTypeWhenMissing not configured: " + e.getMessage());
}

Prevention

When it happens

Trigger: Calling build() without calling setReportTypeWhenMissing(@ReportType int) — or explicitly passing ReportType.UNKNOWN.

Common situations: Developers set the infectiousness fallback but forget the report-type fallback, or mistakenly pass ReportType.UNKNOWN thinking it means 'any'.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of microg/GmsCore@157c9d86ac (2026-09-06). Data as JSON: /api/errors/75a89c5be2576518. Report an issue: GitHub.