Sam deploy fails on missing /tmp folder files

[SodaDev]

Title

Bug: sam deploy fails on v1.160.0 with nested app template lookup in /tmp (Template file not found at /tmp/lambdaName/template.yaml)

Description

After upgrading AWS SAM CLI from 1.159.1 to 1.160.0, deployment started failing for a project using nested AWS::Serverless::Application templates with

Transform:

• AWS::LanguageExtensions
• AWS::Serverless-2016-10-31

The same pipeline and templates work on 1.159.1.

Failure message:
Error: Template file not found at /tmp/lambdaName/template.yaml

Steps to reproduce

1. Use a parent template (e.g. deployments/template.yaml) with nested applications:

Resources:
  lambdaName:
    Type: AWS::Serverless::Application
    Properties:
      Location: lambdaName/template.yaml

I believe the issue is related to LanguageExtensions logic, but it breaks already existing artifacts.

[SodaDev]

Here is some AI investigation on the case

Title

Bug: sam deploy regression in v1.160.0 with AWS::LanguageExtensions + nested AWS::Serverless::Application (Location not packaged, lookup fails under /tmp)

Description

After upgrading AWS SAM CLI from 1.159.1 to 1.160.0, deploy started failing for templates that use:

• Transform: [AWS::LanguageExtensions, AWS::Serverless-2016-10-31]
• nested apps via AWS::Serverless::Application and local Location paths (e.g. ./PublisherApi/template.yaml)

Observed error:

Error: Template file not found at /tmp/PublisherApi/template.yaml

The same project and pipeline work on 1.159.1.

---

Repro (minimal pattern)

Parent template:

Transform:
  - AWS::LanguageExtensions
  - AWS::Serverless-2016-10-31

Resources:
  PublisherApi:
    Type: AWS::Serverless::Application
    Properties:
      Location: ./PublisherApi/template.yaml

Deploy command:

sam deploy --template-file deployments/template.yaml --s3-bucket <bucket> ...

---

Expected result

SAM packages/uploads nested app template referenced by AWS::Serverless::Application.Properties.Location, and deployment succeeds.

Observed result

During deploy/package flow on 1.160.0, nested app template path remains local and later resolves relative to temp working area, causing lookup failure under /tmp/....

---

Regression window

• Works: v1.159.1
• Fails: v1.160.0

---

Code-level root cause (likely)

v1.160.0 introduced new language-extensions packaging flow that preserves original template shape and merges packaged artifact URIs back.

In that new flow, artifact-property copy is gated by:

• samcli/lib/cfn_language_extensions/models.py
  • PACKAGEABLE_RESOURCE_ARTIFACT_PROPERTIES

and merge logic in:

• samcli/lib/package/language_extensions_packaging.py
  • merge_language_extensions_s3_uris
  • _copy_artifact_uris_for_type

PACKAGEABLE_RESOURCE_ARTIFACT_PROPERTIES includes:

• AWS::CloudFormation::Stack -> TemplateURL

but does not include:

• AWS::Serverless::Application -> Location

So in the language-extensions branch, nested app Location is not rewritten to packaged S3/template URI and remains local. Later path resolution happens in temp context (/tmp) and fails with:
/tmp/PublisherApi/template.yaml.

---

Suggested fix

Add AWS::Serverless::Application mapping to PACKAGEABLE_RESOURCE_ARTIFACT_PROPERTIES:

# samcli/lib/cfn_language_extensions/models.py
PACKAGEABLE_RESOURCE_ARTIFACT_PROPERTIES = {
    ...
    "AWS::CloudFormation::Stack": ["TemplateURL"],
    "AWS::Serverless::Application": ["Location"],  # missing mapping
}

This should allow the new language-extensions packaging path to handle nested app templates consistently with pre-1.160 behavior.

---

Workaround

Pin SAM CLI to 1.159.1 in pipeline (current workaround in use).

---

Environment

• SAM CLI: 1.160.0 (failing), 1.159.1 (working)
• OS: macOS local + Linux CI
• Template uses AWS::LanguageExtensions

[roger-zhangg]

Thanks for reporting, we are taking a look now. In the meantime, you can downgrade to (https://github.com/aws/aws-sam-cli/releases/tag/v1.159.1) to unblock.

[github-actions]

⚠️COMMENT VISIBILITY WARNING⚠️

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.

[roger-zhangg]

This is fixed in our new release: https://github.com/aws/aws-sam-cli/releases/tag/v1.160.1

[SodaDev]

Confirmed that it works. Thank you for the quick fix!