Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

Ruby Layers not properly packaged

Open
  • Is something wrong?
#177 3 comments 5 reactions 0 assignees View on GitHub

Maintainers usually reply within 2 days

Nobody has claimed this yet.

Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
aws, ruby
Domain
build-system, cloud

Research direction

Reproduce the issue with the SAMBuildLayer example, its Gemfile, and sam build, then inspect .aws-sam/build for the resulting layer layout. Compare the bundled gems with the documented ruby/gems/2.7.0 and ruby/lib paths; done means a sample function can find the Gem without the Makefile workaround.

Written by the indexing model from the issue text.

Description

area/workflow/ruby_bundler maintainer/need-response

Description:

When using SAM to build a Ruby layer, packaging of Gems is incorrect. Gems are bundled in ruby /lib/vendor/bundle/ruby/2.7.0 using the default bundler workflow, these Gems are not picked up by the runtime.

Per documentation, GEM_PATH (ruby/gems/2.7.0) should be used. Shared / custom code is packaged properly to RUBYLIB (ruby/lib).

Steps to reproduce the issue:

  1. Create new SAM application.
  2. Add Layer to template:
SAMBuildLayer:
    Type: AWS::Serverless::LayerVersion
    Properties:
      ContentUri: SAMBuild
      CompatibleRuntimes:
        - ruby2.7
    Metadata:
      BuildMethod: ruby2.7
  1. Add directory SAMBuild containing a Gemfile with valid contents.
  2. Run sam build command.
  3. Review results and/or test with a sample function.

Observed result:

Result of build (.aws-sam/build) contains SAMBuildLayer/ruby/lib/vendor/bundle/ruby/2.7.0/gems with bundled Gems. When attempting to run sample function, Gem is not found.

Expected result:

Gem should be packaged in ruby/gems/2.7.0 and available to function when executed. I was able to build using a Makefile:

MakeBuildLayer:
  Type: AWS::Serverless::LayerVersion
  Properties:
    ContentUri: MakeBuild
    CompatibleRuntimes:
      - ruby2.7
  Metadata:
    BuildMethod: makefile

And Makefile in MakeBuild directory:

build-MakeBuildLayer:
  bundle install --path=$(ARTIFACTS_DIR)
  rm -rf $(ARTIFACTS_DIR)/ruby/2.7.0/cache && rm -rf $(ARTIFACTS_DIR)/ruby/2.7.0/bin
  mkdir $(ARTIFACTS_DIR)/ruby/gems
  mv $(ARTIFACTS_DIR)/ruby/2.7.0 $(ARTIFACTS_DIR)/ruby/gems

Additional environment details (Ex: Windows, Mac, Amazon Linux etc)

SAM CLI, version 0.52.0

Dominant language
Python
Stars
381
Forks
164
Avg merge
1d 1h
Merged PRs (30d)
2

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from aws/aws-lambda-builders

All issues in aws/aws-lambda-builders

Similar issues

More Python issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.