=== RUN   TestΔBTail/Update/T7/B1:a,2:b-B8:c,9:d→T3/T-T/B1:a,2:b-B8:c,9:d
    δbtail_test.go:832: 2: trackSet:
                have: map[000000000000000c:{pffffffffffffffff c2} 0000000000000041:{p0000000000000043 c0} 0000000000000042:{p0000000000000044 c0} 0000000000000043:{p000000000000000c c1} 0000000000000044:{p000000000000000c c1}]
                want: map[000000000000000c:{pffffffffffffffff c1} 0000000000000041:{p0000000000000043 c0} 0000000000000043:{p000000000000000c c1}]
    δbtail_test.go:708: T7/B1:a,2:b-B8:c,9:d -> T3/T-T/B1:a,2:b-B8:c,9:d  ; tracked={1} :

        d12:  map[]
        δTok: map[]
        δT:   map[]

        δZ:               {000000000000000c 0000000000000043 0000000000000044}
        Tracked^δZ:       {}
        kadj[Tracked^δZ]: {}
        kadj: map[1:{1 2 8 9 9223372036854775807} 2:{1 2 8 9 9223372036854775807} 8:{1 2 8 9 9223372036854775807} 9:{1 2 8 9 9223372036854775807} 9223372036854775807:{1 2 8 9 9223372036854775807}]

        δtkeycov wrong:
        have: {[7,∞)}
        want: {}