Process.info/2 weirdness

iex

iex(1)> pid = spawn fn -> end
#PID<0.61.0>
iex(2)> Process.info(pid, :status)
nil
iex(3)> Process.info(pid, :status)
nil
iex(4)>

process_info.exs

pid = spawn fn -> end
IO.inspect Process.info(pid, :status) # {:status, :runnable}
IO.inspect Process.info(pid, :status) # nil

test-lib-process_test.exs

test "info/2" do
  pid = spawn fn -> end
  assert Process.info(pid, :status) == {:status, :runnable}
  assert Process.info(pid, [:status]) == [status: :runnable]

  Process.exit(pid, :kill)
  assert Process.info(pid, :backtrace) == nil
  assert Process.info(pid, [:backtrace, :status]) == nil
end

# specs are passing