Fix Bundler crashing when installing very old gems:

[Edouard-chin]

What was the end-user or developer problem that led to this PR?

There is a regression where bundler can no longer install gems that were packaged a long time ago, like the memoize gem.

Bundler will crash with such error:

Installing memoize 1.3.1
--- ERROR REPORT TEMPLATE -------------------------------------------------------

NoMethodError: undefined method 'as_list' for nil /Users/edouard/src/opensource/rubygems/lib/rubygems/dependency.rb:146:in 'Gem::Dependency#requirements_list'

What is your fix for the problem, implemented in this PR?

Context

These very old gems were packaged at the time were a Gem::Dependency had no ivars requirement. This is what the dumped gemspec looks like:

dependencies: 
- !ruby/object:Gem::Dependency 
  name: test-unit
  type: :development
  version_requirement: 
  version_requirements: !ruby/object:Gem::Requirement 
    requirements: 
    - - ">="
      - !ruby/object:Gem::Version 
        version: 2.0.2
    version: 

As opposed to a gem that was packaged more recently:

- !ruby/object:Gem::Dependency
  name: minitest-global_expectations
  requirement: !ruby/object:Gem::Requirement
    requirements:
    - - ">="
      - !ruby/object:Gem::Version
        version: '0'
  type: :development
  prerelease: false
  version_requirements: !ruby/object:Gem::Requirement
    requirements:
    - - ">="
      - !ruby/object:Gem::Version
        version: '0'

The change we made in cbe57bb#diff-5ccc8aa468df013cc970580e88642417da12284da6529a4885b9abf447ae95edL529 broke old gem installation.

Solution

If requirement isn't set in the hash, look for version_requirements instead.

Make sure the following tasks are checked

• Describe the problem / feature
• Write tests for features and bug fixes
• Write code to solve the problem
• Make sure you follow the current code style and write meaningful commit messages without tags

cc/ @hsbt Let me know if this fix is acceptable

[hsbt]

🙏 Thanks!

Is this gem being used in application on Shopify? Currently, I'm testing based on download numbers, but we're looking for a more effective way to find it.

[Edouard-chin]

Is this gem being used in application on Shopify?

Nop, it's not. It's used in my benchmarks only