Description
ePIC recently upgraded ACTS to 36.3.2, and noticed that both measurement and outlier hits are associated with the trajectory as measurements, while chi2, nMeasurements, nOutliers behaves normal, see eic/EICrecon#1918 (comment)
With further investigation, we noticed that this change in ACTS 36.1 gives all measurement candidate a measurement flag regardless of the isOutlier condition. Because the TrackStateFlag uses bitset, this change produces outlier hits with both measurement and outlier bits set to true.
If there's no change in the definition of measurement (measurement candidate that is used in a given trajectory) and outlier (candidate exists on the surface but not used due to chi2 cut) ,can we modify the relevant code to keep the measurement and outlier status mutually exclusive?