Bundler repro case for #6072

actionpack.gemspec

Gem::Specification.new do |s|
  s.name        = "actionpack"
  s.version     = "5.1.4"
  s.summary     = ""
  s.description = ""
  s.author      = "David Heinemeier Hansson"

  s.add_dependency "rack",      "~> 2.0"
end

inline.rb

require 'bundler/inline'
gemfile(true) do
  source "https://rubygems.org"
  gem "rails", path: "."
end

require 'rake'
puts Rake::VERSION

rails.gemspec

Gem::Specification.new do |s|
  s.name        = "rails"
  s.version     = "5.1.4"
  s.summary     = ""
  s.description = ""
  s.author      = "David Heinemeier Hansson"

  s.add_dependency "actionpack", "5.1.4"
end

repro.sh

#!/bin/sh
ruby inline.rb && ruby inline.rb