Stack: Can't run stack with cross region reference with --exclusively flag

[Cabeda]

Describe the bug

I have a cross region project (using crossRegionReferences) with 3 stacks. Two are deployed in eu-central-1 and the other (cloudfront distribution) is on us-east-1.

If I run cdk deploy -e stack-common it works perfectly. However if I run the cdk deploy -e stack-cloudfront it fails with:

❌ stack-common failed: ToolkitError: Failed to create ChangeSet cdk-deploy-change-set on stack-common: FAILED, Parameters: [ssm:/cdk/exports/stack-common/<resource>] cannot be found.

I know the distribution exists in us-east-1 and I can see the parameter exists. This problem is resolved if I run without the flag --exclusively.

Regression Issue

• Select this option if this issue appears to be a regression.

Last Known Working CDK Library Version

No response

Expected Behavior

Running cdk deploy --exclusively shouldn't report that resource cannot be found

Current Behavior

❌ stack-common failed: ToolkitError: Failed to create ChangeSet cdk-deploy-change-set on stack-common: FAILED, Parameters: [ssm:/cdk/exports/stack-common/] cannot be found. `

Reproduction Steps

cdk deploy -e stack-us-east-1
cdk deploy -e stack-outside us-east-1

Possible Solution

No response

Additional Information/Context

No response

AWS CDK Library version (aws-cdk-lib)

2.221.1

AWS CDK CLI version

2.1029.2

Node.js Version

22.22.1

OS

macos 26.1

Language

Python

Language Version

python 3.12.10

Other information

No response

[pahud]

Hi @Cabeda,

Thank you for reporting this issue. I was not able to reproduce as no reproduction code snippets are provided. But based on the error message and behavior you've described, this appears to be a limitation in how the --exclusively flag interacts with cross-region references.

Since I can't see your code, I'm making some assumptions about your setup, but here's what appears to be happening:

When you use crossRegionReferences, CDK creates infrastructure to share values between stacks in different regions using SSM parameters. The exporting stack (stack-common in eu-central-1) needs to write these parameters to the importing stack's region (us-east-1) during deployment. The importing stack (stack-cloudfront) then reads these parameters.

The issue likely occurs because the --exclusively flag bypasses the normal dependency resolution. When you deploy only stack-cloudfront with -e, the SSM parameters haven't been created yet because stack-common (which creates them) hasn't been deployed.

Workaround:
Try deploying the dependency stack first, then use --exclusively for the dependent stack:

cdk deploy stack-common
cdk deploy -e stack-cloudfront

Or deploy without the --exclusively flag to let CDK handle the dependency order:

cdk deploy stack-cloudfront

Root Cause (likely):

The --exclusively flag is designed to deploy only the specified stack without its dependencies. However, with cross-region references, the dependency stack must be deployed first to create the SSM parameters in the target region.

If you can share more details about your code to allow me to reproduce on my end, that would be helpful.

[pahud]

OK I was able to reproduce it with --exclusive and it works without --exclusive.

❌ stack-cloudfront failed: ToolkitError: Failed to create ChangeSet cdk-deploy-change-set on stack-cloudfront: FAILED, Parameters: [ssm:/cdk/exports/stack-cloudfront/stackcommoneucentral1FnGetAttBucket83908E77RegionalDomainNameB5984C34] cannot be found.

Root Cause:

The --exclusively flag bypasses dependency resolution, so the exporting stack (stack-common) never deploys, the SSM parameters are never created, and the importing stack (stack-
cloudfront) fails when trying to read them.

Here's the minimal CDK code used for reproduction:

#!/usr/bin/env node
import * as cdk from 'aws-cdk-lib/core';
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as cloudfront from 'aws-cdk-lib/aws-cloudfront';

const app = new cdk.App();

// Stack in eu-central-1 that exports a value
const commonStack = new cdk.Stack(app, 'stack-common', {
  env: { region: 'eu-central-1' },
  crossRegionReferences: true,
});

const bucket = new s3.Bucket(commonStack, 'Bucket');

// Stack in us-east-1 that imports the value
const cloudfrontStack = new cdk.Stack(app, 'stack-cloudfront', {
  env: { region: 'us-east-1' },
  crossRegionReferences: true,
});

new cloudfront.CloudFrontWebDistribution(cloudfrontStack, 'Distribution', {
  originConfigs: [{
    s3OriginSource: {
      s3BucketSource: bucket,
    },
    behaviors: [{ isDefaultBehavior: true }],
  }],
});

Key elements:
• Two stacks in different regions (eu-central-1 and us-east-1)
• Both have crossRegionReferences: true
• stack-cloudfront references a resource (bucket) from stack-common
• This creates a cross-region dependency

Commands to reproduce:

# Initialize CDK app
npx cdk init app --language typescript

Replace bin/[app-name].ts with the code above

# This FAILS:
npx cdk deploy -e stack-cloudfront --require-approval never


# This WORKS:
npx cdk deploy stack-cloudfront --require-approval never

[sai-ray]

Analysis Complete

After investigating this issue, the root cause has been identified:

This is a CDK CLI issue, not an aws-cdk-lib issue.

The aws-cdk-lib code correctly:

1. Creates Custom::CrossRegionExportWriter and Custom::CrossRegionExportReader custom resources
2. Establishes stack dependencies via consumer.addDependency(producer) in refs.ts
3. Stores dependencies in the cloud assembly manifest

The issue is that the CLI's --exclusively flag bypasses this dependency resolution. When CloudFormation tries to resolve the SSM dynamic references ({{resolve:ssm:...}}), the parameters don't exist because the producing stack was skipped.

Transferred to: #1130

The fix should be implemented in the CDK CLI to detect cross-region dependencies when --exclusively is used and warn the user appropriately.