A class with a new constant name can be rescued by either name

rescue_proof.rb

[3] pry(main)> class E1 < RuntimeError
[3] pry(main)* end
=> nil
[4] pry(main)> E2 = E1
=> E1
[5] pry(main)> E2
=> E1
[6] pry(main)> def r1
[6] pry(main)*   raise E2
[6] pry(main)* rescue E1
[6] pry(main)*   :rescued
[6] pry(main)* end
=> :r1
[7] pry(main)> def r2
[7] pry(main)*   raise E1
[7] pry(main)* rescue E2
[7] pry(main)*   :rescued
[7] pry(main)* end
=> :r2
[8] pry(main)> r1
=> :rescued
[9] pry(main)> r2
=> :rescued