tree 3fc3b1dc23f5acc094b3c75c7b7be91f70ac864c
parent 9b593402251b9c64e5fd99659fa0033ed2775547
author Oliver Newman <olivernewman@google.com> 1716396716 +0000
committer CQ Bot <fuchsia-internal-scoped@luci-project-accounts.iam.gserviceaccount.com> 1716396716 +0000

[cipd-resolver] Ensure deterministic tag ordering

If a package has multiple tags with the same timestamp, fall back to
sorting by tag value to ensure determinism - otherwise the ordering
would be nondeterministic (since it depends on map ordering), leading to
nondeterministic behavior.

This was manifesting in the recipe-tools-roller when it encountered a
package whose latest instance had multiple tags with the same key but
different values, and one of those two tags was duplicated on another
instance, making it unresolvable. So the roller's behavior varied
depending on which tag it happened to check first:
https://screenshot.googleplex.com/4XN6rpBFzzfRrCL

Bug: 341709889
Change-Id: I1d1f150e3118c2e863aee3914c66d7f8d1d07220
Reviewed-on: https://fuchsia-review.googlesource.com/c/infra/infra/+/1050394
Fuchsia-Auto-Submit: Oliver Newman <olivernewman@google.com>
Reviewed-by: Danielle Kay <danikay@google.com>
Reviewed-by: David Fang <fangism@google.com>
Commit-Queue: Auto-Submit <auto-submit@fuchsia-infra.iam.gserviceaccount.com>