basalt-26.3.2-rc-20260913: kv/kvserver: TestStoreRangeMergeSplitRace_MergeWins failed

kv/kvserver.TestStoreRangeMergeSplitRace_MergeWins [failed](https://mesolite.cluster.engflow.com/invocations/default/0c3ca5ba-4f79-4bf2-92cd-90e079bf4004?testReportRun=3&testReportShard=13&testReportAttempt=1#targets-Ly9wa2cva3Yva3ZzZXJ2ZXI6a3ZzZXJ2ZXJfdGVzdA==) on basalt-26.3.2-rc-20260913 @ [c6a822fb5ec0b622c713fccacb82159d1b60bbcd](https://github.com/cockroachdb/cockroach/commits/c6a822fb5ec0b622c713fccacb82159d1b60bbcd):

```
=== RUN TestStoreRangeMergeSplitRace_MergeWins
test_log_scope.go:172: test logs captured to: outputs.zip/logTestStoreRangeMergeSplitRace_MergeWins745120525
test_log_scope.go:82: use -show-logs to present logs inline
test_server_shim.go:146: using test tenant configuration from testserver factory defaults
client_merge_test.go:1655: merge failed: checking RHS manifest before merge: descriptor generation mismatch: expected 2, found 3
panic.go:694: -- test log scope end --
test logs left over in: outputs.zip/logTestStoreRangeMergeSplitRace_MergeWins745120525
--- FAIL: TestStoreRangeMergeSplitRace_MergeWins (5.29s)
```

Parameters:
- attempt=1
- race=true
- run=3
- shard=13
Help

See also: [How To Investigate a Go Test Failure \(internal\)](https://cockroachlabs.atlassian.net/l/c/HgfXfJgM)

Same failure on other branches

- #175040 basalt-26.3: kv/kvserver: TestStoreRangeMergeSplitRace_MergeWins failed [C-test-failure O-robot P-3 T-kv X-duplicate branch-basalt-26.3]
- #174984 basalt-26.3.2-rc-20260908: kv/kvserver: TestStoreRangeMergeSplitRace_MergeWins failed [C-test-failure O-robot P-3 T-kv X-duplicate branch-basalt-26.3.2-rc-20260908]
- #174777 kv/kvserver: TestStoreRangeMergeSplitRace_MergeWins failed [A-testing C-bug C-test-failure O-robot P-3 T-kv branch-master]

/cc @cockroachlabs/kv-triage

[This test on roachdash](https://roachdash.crdb.dev/?filter=status:open%20t:.*TestStoreRangeMergeSplitRace_MergeWins.*&sort=title+created&display=lastcommented+project) | [Improve this report!](https://github.com/cockroachdb/cockroach/tree/master/pkg/cmd/bazci/githubpost/issues)

Start with kv/kvserver.TestStoreRangeMergeSplitRace_MergeWins and the failure at client_merge_test.go:1655. Inspect the linked test logs and compare duplicate reports #175040, #174984, and #174777 to determine whether the descriptor generation mismatch is understood. Done means the race test no longer fails across the affected branches.

Written by the indexing model from the issue text.