Sandbox seed ignores identifier arg

[MattiNuutinen]

Environment information

System:
  OS: macOS 15.4
  CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
  Memory: 55.20 MB / 32.00 GB
  Shell: /bin/zsh
Binaries:
  Node: 20.19.0 - ~/.nvm/versions/node/v20.19.0/bin/node
  Yarn: 1.22.22 - /usr/local/bin/yarn
  npm: 10.8.2 - ~/.nvm/versions/node/v20.19.0/bin/npm
  pnpm: 8.15.9 - ~/.nvm/versions/node/v20.19.0/bin/pnpm
NPM Packages:
  @aws-amplify/auth-construct: 1.8.1
  @aws-amplify/backend: 1.16.1
  @aws-amplify/backend-ai: Not Found
  @aws-amplify/backend-auth: 1.7.1
  @aws-amplify/backend-cli: 1.7.1
  @aws-amplify/backend-data: 1.6.1
  @aws-amplify/backend-deployer: 2.1.1
  @aws-amplify/backend-function: 1.14.1
  @aws-amplify/backend-output-schemas: 1.6.0
  @aws-amplify/backend-output-storage: 1.3.1
  @aws-amplify/backend-secret: 1.4.0
  @aws-amplify/backend-storage: 1.4.1
  @aws-amplify/cli-core: 2.1.1
  @aws-amplify/client-config: 1.7.0
  @aws-amplify/data-construct: 1.16.1
  @aws-amplify/data-schema: 1.20.4
  @aws-amplify/deployed-backend-client: 1.7.0
  @aws-amplify/form-generator: 1.2.1
  @aws-amplify/model-generator: 1.2.0
  @aws-amplify/platform-core: 1.9.0
  @aws-amplify/plugin-types: 1.10.1
  @aws-amplify/sandbox: 2.1.1
  @aws-amplify/schema-generator: 1.4.0
  @aws-cdk/toolkit-lib: 0.3.2
  aws-amplify: 6.14.2
  aws-cdk-lib: 2.189.1
  typescript: 5.8.3

Describe the bug

Using sandbox seed cli with --identifier argument fails as default userprofile based identifier is used instead.

For example:
npx ampx sandbox seed --identifier test-id

Fails:
[StackDoesNotExistError] Stack does not exist.
∟ Caused by: [Error] Stack with id amplify-project-user-sandbox-a239e2352a does not exist
Resolution: Ensure the CloudFormation stack ID or Amplify App ID and branch specified are correct and exists, then re-run this command.

Seems that issue is caused (packages/cli/src/commands/sandbox/sandbox-seed/sandbox_seed_command.ts#41 const backendID = await this.backendIDResolver.resolve(); missing optional identifier.

Reproduction steps

• Create sandbox with identifier npx ampx sandbox --identifier test-id
• Run seed for sandbox with identifier npx ampx sandbox seed --identifier test-id

[ShadowCat567]

I was able to verify this behavior and noticed it also affects seed's generate policy command. Marking this as a bug to be fixed.

[sobolk]

Fix was shipped in latest release.