The following two build machine environment differences cause the generated CDS classlist to differ:

1) On Linux platforms: ipv6 enabled or disabled:
  Causes the following differences in classlist:
    $ diff ipv6_classlist no_ipv6_classlist
355d354
< java/net/DefaultInterface
358,360d356
< java/net/Inet6Address
< java/net/Inet6Address$Inet6AddressHolder
< java/net/Inet6AddressImpl
366,367d361
< java/net/InterfaceAddress
< java/net/NetworkInterface

2) On at least Windows platforms a TimeZone difference, eg.UTC vs PDT:
  Causes the following differences in classlist:
$ diff UTC_classlist PDT_classlist
1427a1428
> sun/util/calendar/ZoneInfoFile$Checksum
1733c1734
< @cp java/lang/invoke/VarHandleByteArrayAsLongs$ArrayHandle 4 9 14 28 29 34 36 37 86
---
> @cp java/lang/invoke/VarHandleByteArrayAsLongs$ArrayHandle 4 9 14 22 28 29 34 36 37 45 46 55 56 65 66 86
2429c2430
< @cp jdk/internal/misc/Unsafe 2 7 8 13 22 107 281 306 307 316 351 693 932
---
> @cp jdk/internal/misc/Unsafe 2 7 8 13 22 107 281 306 307 316 326 351 693 932
2489c2490
< @cp jdk/internal/util/ByteArray 8 14 19 26 31 94 95 101
---
> @cp jdk/internal/util/ByteArray 8 14 19 26 31 49 94 95 101
2597c2598
< @cp sun/util/calendar/ZoneInfoFile 1 3 16 43 57 78 83 88 99 103 107 109 171 175 228 241 411 414 520 525 526 543
---
> @cp sun/util/calendar/ZoneInfoFile 1 3 16 43 57 78 83 88 99 103 107 109 171 175 228 241 257 295 299 302 305 308 312 315 318 321 324 370 388 411 414 520 525 526 543
2598a2600,2601
> @cp sun/util/calendar/ZoneInfoFile$Checksum 2 8 28
> @cp sun/util/calendar/ZoneInfoFile$ZoneOffsetTransitionRule 1 4 10 17 18 24 28 31 34 37 40 43 64 109