Gem::Resolver#compute_dependencies

# File tmp/rubies/ruby-4.1.0-preview1/lib/rubygems/resolver.rb, line 499
def compute_dependencies(package, version)
  spec = spec_for(package.to_s, version)
  return {} unless spec
  return {} if @ignore_dependencies

  spec.fetch_development_dependencies if @development && spec.respond_to?(:fetch_development_dependencies)

  deps = {}
  root_names = @needed.map(&:name)

  spec.dependencies.each do |d|
    next if d.name == package.to_s
    next if d.type == :development && !@development
    next if d.type == :development && @development_shallow && !root_names.include?(package.to_s)

    dep_package = package_for(d.name)

    # In force mode, skip deps that can't be satisfied - either no
    # specs at all, or no specs matching the version requirement.
    if @soft_missing
      dep_specs = @all_specs[d.name]
      matching = dep_specs.select {|s| d.requirement.satisfied_by?(s.version) }
      next if matching.empty?
    end

    deps[d.name] = Gem::PubGrub::RubyGems.requirement_to_constraint(dep_package, d.requirement)
  end

  deps
end