semaphoreui/semaphore · error

expected bool for field, got %T

Error message

expected bool for field, got %T

What it means

Inside setBasicType (services/project/backup_marshal.go:119), when the destination field's reflect.Kind is Bool, the incoming JSON data must be a Go bool (JSON true/false). If data is any other type (string, number, null, map), the function returns "expected bool for field, got %T" naming the actual Go type received. It exists to prevent reflect panics from SetBool on non-bool data.

Solutions

1. Open the backup JSON, find the field, and change its value to a real JSON boolean (true/false, unquoted).
2. If the field is genuinely numeric in your data, change the Go struct field type to match (int/float) instead of bool.
3. Pre-validate the backup file (jq -e '... | type == "boolean"') before running the restore.
4. Re-export the backup with a compatible version of the tool so types match the current struct definitions.

Example fix

// before (backup.json)
"allow_pprof": "true"
// after
"allow_pprof": true

// before restore, check field type
var raw map[string]any
json.Unmarshal(backupData, &raw)
if v, ok := raw["allow_pprof"]; ok {
    if _, ok := v.(bool); !ok { return fmt.Errorf("field allow_pprof must be bool, got %T", v) }
}

func isBool(v any) bool { _, ok := v.(bool); return ok }

if err := project.Unmarshal(data, &target); err != nil {
    var te *project.TypeError // or inspect message
    if strings.Contains(err.Error(), "expected bool for field") {
        return fmt.Errorf("invalid backup: %w", err)
    }
    return err
}

When it happens

Trigger: unmarshalValueWithBackupTags encounters a backup-tagged bool struct field whose JSON value is not a boolean - e.g. a string "true", the number 1, or null from the backup file.

Common situations: Hand-edited backup JSON where a boolean field was written as "true" (string) or 1; backups exported from older/newer schema versions where a field changed from int to bool; JSON produced by another tool that serializes booleans as strings.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• expected string for field, got %T
• expected number for field, got %T
• expected object for struct, got %T
• must be valid JSON
• key can not be empty

AI-assisted analysis of semaphoreui/semaphore@1774ccb71a (2026-09-07). Data as JSON: /api/errors/d2be117dd0c8a36e. Report an issue: GitHub.

Appendix: source

Thrown at services/project/backup_marshal.go:119

			result[mapKey] = mapValue
		}
		return result, nil
	}

	// Handle other types (int, string, etc.)
	return v.Interface(), nil
}

func setBasicType(data any, v reflect.Value) error {
	if !v.CanSet() {
		return fmt.Errorf("cannot set value")
	}

	switch v.Kind() {
	case reflect.Bool:
		b, ok := data.(bool)
		if !ok {
			return fmt.Errorf("expected bool for field, got %T", data)
		}
		v.SetBool(b)
	case reflect.String:
		s, ok := data.(string)
		if !ok {
			return fmt.Errorf("expected string for field, got %T", data)
		}
		v.SetString(s)
	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
		n, ok := toFloat64(data)
		if !ok {
			return fmt.Errorf("expected number for field, got %T", data)
		}
		v.SetInt(int64(n))
	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
		n, ok := toFloat64(data)
		if !ok {
			return fmt.Errorf("expected number for field, got %T", data)

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