workload/rand: TestDiffRandomSchema failed

workload/rand.TestDiffRandomSchema [failed](https://mesolite.cluster.engflow.com/invocations/default/9d9e1677-5b2c-4628-ac21-e29ba3e808d1?testReportRun=2&testReportShard=3&testReportAttempt=1#targets-Ly9wa2cvd29ya2xvYWQvcmFuZDpyYW5kX3Rlc3Q=) on release-25.4.15-rc @ [7b399e713413017b73672b6a21d1e1463b2ca97f](https://github.com/cockroachdb/cockroach/commits/7b399e713413017b73672b6a21d1e1463b2ca97f):

```
=== RUN TestDiffRandomSchema
test_log_scope.go:171: test logs captured to: outputs.zip/logTestDiffRandomSchema3378184267
test_log_scope.go:82: use -show-logs to present logs inline
test_server_shim.go:154: automatically injected a shared process virtual cluster under test; see comment at top of test_server_shim.go for details.
diff_test.go:207: random seed: 6214119848281220504
diff_test.go:227: attempt 0 schema: CREATE TABLE t (col0_0 PG_LSN, col0_1 REGCLASS NULL, col0_2 BOX2D NOT NULL, col0_3 REGTYPE, col0_4 BIT(40) NOT NULL, col0_5 STRING COLLATE de_DE NOT NULL, col0_6 GEOMETRY NOT NULL, col0_7 INT4 NOT NULL, col0_8 TIMESTAMP NOT NULL, col0_9 GEOMETRY NULL, col0_10 FLOAT8 NULL, col0_11 BYTES NULL, col0_12 INET NOT NULL, col0_13 OID, col0_14 OID NULL, col0_15 STRING NOT NULL AS (lower(CAST(col0_2 AS STRING))) STORED, PRIMARY KEY (col0_2 ASC))
diff_test.go:227: attempt 1 schema: CREATE TABLE t (col0_0 BIT NOT NULL, col0_1 TSVECTOR NULL, PRIMARY KEY (col0_0), INDEX (col0_0 DESC) STORING (col0_1), INVERTED INDEX (col0_0 DESC, col0_1))
diff_test.go:281: -- test log scope end --
test logs left over in: outputs.zip/logTestDiffRandomSchema3378184267
--- FAIL: TestDiffRandomSchema (5.64s)
=== RUN TestDiffRandomSchema/fingerprint-diff-1
diff_test.go:275:
Error Trace: pkg/workload/rand/diff_test.go:275
Error: Should NOT be empty, but was []
Test: TestDiffRandomSchema/fingerprint-diff-1
Messages: fingerprints differ (a=8390965314099546353, b=-3720589183424384675) but Diff returned no differences
--- FAIL: TestDiffRandomSchema/fingerprint-diff-1 (0.05s)
```

Parameters:
- attempt=1
- run=2
- shard=3
Help

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

/cc @cockroachlabs/cdc

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

Start with pkg/workload/rand/diff_test.go, especially TestDiffRandomSchema and its fingerprint-diff-1 subtest, then inspect the linked test logs for the failing random schemas. Determine why Diff returns no differences despite differing fingerprints, and confirm that the test passes for this reported case.

Written by the indexing model from the issue text.