Proof of concept for https://github.com/pry/pry/issues/779

find_ref.rb

class RefThroughClosure
  attr_reader :inspect                                    # => nil
  def initialize(object)
    @inspect = "#<RefThroughClosure(#{object.inspect})>"  # => "#<RefThroughClosure(:dont_track_me_bro)>"
    @context = lambda { }                                 # => #<Proc:0x007fa7fa03ff80@/Users/josh/Desktop/find_refs.rb:5 (lambda)>
  end
end

class RefThroughIvar
  attr_reader :inspect                                # => nil
  def initialize(object)
    @inspect = "#<RefThroughIvar(#{object.inspect})"  # => "#<RefThroughIvar(:dont_track_me_bro)"
    @object = object                                  # => :dont_track_me_bro
  end
end

module FindRef
  def self.call(target)
    found = {}                                                                                                   # => {}
    ObjectSpace.each_object(Proc) { |prc|                                                                        # => ObjectSpace
      binding = prc.binding rescue next                                                                          # => #<Binding:0x007fa7f9962e88>, #<Binding:0x007fa7f9961f88>, #<Binding:0x007fa7f9961448>, #<Binding:0x007fa7f9960a48>, #<Binding:0x007fa7f9961718>, #<Binding:0x007fa7f9833350>, #<Binding:0x007fa7f9831a28>, #<Binding:0x007fa7f98304c0>, #<Binding:0x007fa7f983bb40>, #<Binding:0x007fa7f983b1e0>, #<Binding:0x007fa7f983a8a8>, #<Binding:0x007fa7f9839fe8>, #<Binding:0x007fa7f9839660>, #<Binding:0x007...
      object  = binding.eval 'self'                                                                              # => SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving::Line, SeeingIsBelieving...
      names_of_locals = binding.eval 'local_variables'                                                           # => [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method_name], [:method...
      locals_that_reference = names_of_locals.select { |name| binding.eval(name.to_s).equal?(target) }           # => [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [:object], []
      next if locals_that_reference.empty?                                                                       # => true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, tr...
      found[object] = {                                                                                          # => #<RefThroughClosure(:dont_track_me_bro)>
        local_names: locals_that_reference,                                                                      # => [:object]
        binding:     binding,                                                                                    # => #<Binding:0x007fa7f9912208>
        closure:     prc,                                                                                        # => #<Proc:0x007fa7fa03ff80@/Users/josh/Desktop/find_refs.rb:5 (lambda)>
      }                                                                                                          # => {:local_names=>[:object], :binding=>#<Binding:0x007fa7f9912208>, :closure=>#<Proc:0x007fa7fa03ff80@/Users/josh/Desktop/find_refs.rb:5 (lambda)>}
    }                                                                                                            # => 98
    ObjectSpace.each_object(Object) { |object|                                                                   # => ObjectSpace
      names_of_ivars = object.instance_variables                                                                 # => [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], ...
      ivars_that_reference = names_of_ivars.select { |name| object.instance_variable_get(name).equal?(target) }  # => [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], [], ...
      next if ivars_that_reference.empty?                                                                        # => true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, true, tr...
      found[object] ||= {}                                                                                       # => {}
      found[object][:ivars] = {ivar_names: ivars_that_reference}                                                 # => {:ivar_names=>[:@object]}
    }                                                                                                            # => 20470
    found                                                                                                        # => {#<RefThroughClosure(:dont_track_me_bro)>=>{:local_names=>[:object], :binding=>#<Binding:0x007fa7f9912208>, :closure=>#<Proc:0x007fa7fa03ff80@/Users/josh/Desktop/find_refs.rb:5 (lambda)>}, #<RefThroughIvar(:dont_track_me_bro)=>{:ivars=>{:ivar_names=>[:@object]}}}
  end
end

dont_track_me_bro   = :dont_track_me_bro                        # => :dont_track_me_bro
ref_through_closure = RefThroughClosure.new(dont_track_me_bro)  # => #<RefThroughClosure(:dont_track_me_bro)>
ref_through_ivar    = RefThroughIvar.new(dont_track_me_bro)     # => #<RefThroughIvar(:dont_track_me_bro)

require 'pp'                        # => true
pp FindRef.call(dont_track_me_bro)  # => {#<RefThroughClosure(:dont_track_me_bro)>=>{:local_names=>[:object], :binding=>#<Binding:0x007fa7f9912208>, :closure=>#<Proc:0x007fa7fa03ff80@/Users/josh/Desktop/find_refs.rb:5 (lambda)>}, #<RefThroughIvar(:dont_track_me_bro)=>{:ivars=>{:ivar_names=>[:@object]}}}

# >> {#<RefThroughClosure(:dont_track_me_bro)>=>
# >>   {:local_names=>[:object],
# >>    :binding=>#<Binding:0x007fa7f9912208>,
# >>    :closure=>
# >>     #<Proc:0x007fa7fa03ff80@/Users/josh/Desktop/find_refs.rb:5 (lambda)>},
# >>  #<RefThroughIvar(:dont_track_me_bro)=>{:ivars=>{:ivar_names=>[:@object]}}}