roachtest: cluster_creation failed

roachtest.cluster_creation [failed](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/20847153?buildTab=log) with [artifacts](https://teamcity.cockroachdb.com/buildConfiguration/Cockroach_Nightlies_RoachtestNightlyAwsBazel/20847153?buildTab=artifacts#/cdc/frontier-persistence-benchmark/interval=10m/tables=10/ranges=1000) on release-26.1 @ [e15b1ecc444676ba53266770e0b758de9ae72d22](https://github.com/cockroachdb/cockroach/commits/e15b1ecc444676ba53266770e0b758de9ae72d22):

```
test cdc/frontier-persistence-benchmark/interval=10m/tables=10/ranges=1000 failed: (test_runner.go:990).func4: in provider: aws: failed to run: aws ec2 run-instances --associate-public-ip-address --count 1 --instance-type m6id.4xlarge --image-id ami-0e83be366243f524a --key-name teamcity-runner-QwczjNpONpmi3wvdfBJYQ-C6ON4= --region us-east-2 --security-group-ids sg-04d72b57e29d671f1 --subnet-id subnet-0258dc9d1b6473d84 --tag-specifications ResourceType=instance,Tags=[{Key=usage,Value=roachtest},{Key=roachtest-branch,Value=release-26-1},{Key=created,Value=2025-12-11T07:44:24Z},{Key=Name,Value=teamcity-20847153-1765437052-31-n4cpu16-0003},{Key=Cluster,Value=teamcity-20847153-1765437052-31-n4cpu16},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-20847153-1765437052-31-n4cpu16},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=amd64}] ResourceType=volume,Tags=[{Key=usage,Value=roachtest},{Key=roachtest-branch,Value=release-26-1},{Key=created,Value=2025-12-11T07:44:24Z},{Key=Name,Value=teamcity-20847153-1765437052-31-n4cpu16-0003},{Key=Cluster,Value=teamcity-20847153-1765437052-31-n4cpu16},{Key=spot,Value=true},{Key=roachprod,Value=true},{Key=cluster,Value=teamcity-20847153-1765437052-31-n4cpu16},{Key=lifetime,Value=12h0m0s},{Key=arch,Value=amd64}] --user-data file:///tmp/aws-startup-script2599156857 --iam-instance-profile Name=roachprod-testing --block-device-mapping file:///tmp/aws-block-device-mapping246025332 --instance-market-options MarketType=spot,SpotOptions={SpotInstanceType=one-time,InstanceInterruptionBehavior=terminate} --output json: stderr:
An error occurred (InsufficientInstanceCapacity) when calling the RunInstances operation (reached max retries: 2): We currently do not have sufficient m6id.4xlarge capacity in the Availability Zone you requested (us-east-2a). Our system will be working on provisioning additional capacity. You can currently get m6id.4xlarge capacity by not specifying an Availability Zone in your request or choosing us-east-2b, us-east-2c.: exit status 254 [owner=test-eng]
```

Parameters:
- cloud=aws
- coverageBuild=false
- cpu=16
- runtimeAssertionsBuild=false
- ssd=0
Help

See: [roachtest README](https://github.com/cockroachdb/cockroach/blob/master/pkg/cmd/roachtest/README.md)

See: [How To Investigate \(internal\)](https://cockroachlabs.atlassian.net/l/c/SSSBr8c7)

Same failure on other branches

- #159040 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.3]
- #159039 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.3]
- #159038 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.3]
- #159032 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.3]
- #159031 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-release-25.2]
- #158857 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #158856 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #158855 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #158854 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]
- #158853 roachtest: cluster_creation failed [O-roachtest O-robot T-testeng X-infra-flake branch-master]

/cc @cockroachdb/test-eng

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

Jira issue: CRDB-57743

Start with the roachtest README and the cdc/frontier-persistence-benchmark failure report, then inspect the cluster-creation entry point that issues the shown AWS run-instances command. Compare the repeated failures across the listed branches and determine the expected handling for unavailable us-east-2a capacity; done means cluster_creation is not reported as failed solely for this capacity error.

Written by the indexing model from the issue text.