[ruby-dev:52213] [Ruby Bug#22015] Success without RUBY_BOX=1, Failure with RUBY_BOX=1

24 Apr 2026

      Issue #22015 has been updated by jneen (Jeanine Adkisson).

Related: #21324, #21977 

I believe this to be related to Symbol#to_proc, as changing `bundler/resolver/spec_group.rb:41` from:

```ruby
      def dependencies
        @dependencies ||= @specs.flat_map(&:expanded_dependencies).uniq.sort
      end
```

to

```ruby
      def dependencies
        @dependencies ||= @specs.flat_map { |s| s.expanded_dependencies }.uniq.sort
      end
```

removes the error.

----------------------------------------
Bug #22015: Success without RUBY_BOX=1, Failure with RUBY_BOX=1
https://bugs.ruby-lang.org/issues/22015#change-117110

* Author: niku (niku _)
* Status: Open
* ruby -v: ruby 4.1.0dev (2026-04-24T13:35:04Z master 52ee497f36) +PRISM [arm64-darwin25]
* Backport: 3.3: UNKNOWN, 3.4: UNKNOWN, 4.0: UNKNOWN
----------------------------------------
```
$ ruby -v
ruby 4.1.0dev (2026-04-24T13:35:04Z master 52ee497f36) +PRISM [arm64-darwin25]
```

```
$ ruby -e 'require "bundler/inline"; gemfile {}'
```

It ran fine as expected, but it failed when I added RUBY_BOX=1.

```
$ RUBY_BOX=1 ruby -e 'require "bundler/inline"; gemfile {}'
ruby: warning: Ruby::Box is experimental, and the behavior may change in the future!
See https://docs.ruby-lang.org/en/master/Ruby/Box.html for known issues, etc.
/Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/rubygems/specification.rb:2064:in 'Gem::Specification#method_missing': undefined method 'expanded_dependencies' for an instance of Gem::Specification (NoMethodError)
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver/spec_group.rb:42:in 'Array#each'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver/spec_group.rb:42:in 'Enumerable#flat_map'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver/spec_group.rb:42:in 'Bundler::Resolver::SpecGroup#dependencies'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver/spec_group.rb:67:in 'Bundler::Resolver::SpecGroup#equivalent?'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver/spec_group.rb:51:in 'Bundler::Resolver::SpecGroup#merge'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:279:in 'block (2 levels) in Bundler::Resolver#all_versions_for'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:278:in 'Array#each'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:278:in 'block in Bundler::Resolver#all_versions_for'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:258:in 'Hash#each'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:258:in 'Enumerable#reduce'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:258:in 'Bundler::Resolver#all_versions_for'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:54:in 'block in Bundler::Resolver#setup_solver'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:378:in 'Bundler::Resolver#filtered_versions_for'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:58:in 'block in Bundler::Resolver#setup_solver'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:169:in 'Bundler::Resolver#versions_for'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:449:in 'block in Bundler::Resolver#prepare_dependencies'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:443:in 'Hash#each'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:443:in 'Enumerable#filter_map'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:443:in 'Bundler::Resolver#prepare_dependencies'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:63:in 'Bundler::Resolver#setup_solver'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/resolver.rb:28:in 'Bundler::Resolver#start'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/definition.rb:750:in 'Bundler::Definition#start_resolution'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/definition.rb:351:in 'Bundler::Definition#resolve'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/definition.rb:253:in 'Bundler::Definition#missing_specs'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/definition.rb:257:in 'Bundler::Definition#missing_specs?'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/inline.rb:64:in 'block in Object#gemfile'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/settings.rb:146:in 'Bundler::Settings#temporary'
        from /Users/niku/.local/share/mise/installs/ruby/4.1-dev/lib/ruby/4.1.0+1/bundler/inline.rb:60:in 'Object#gemfile'
        from -e:1:in '<main>'
```

-- 
https://bugs.ruby-lang.org/