Improve debug log -add remote debuggee backlog

[ono-max]

Now, logs of remote debugee doesn't show in failure message. This PR fix it.

Example

Failure: test_foo(DEBUGGER__::FooTest):
  TIMEOUT ERROR (10 sec) on UNIX DOMAIN SOCKET mode
  [DEBUGGER SESSION LOG]
  > [1, 9] in /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb
  > =>    1| module Foo
  >       2|   class Bar
  >       3|     def self.a
  >       4|       p "hello"
  >       5|     end
  >       6|   end
  >       7|   Bar.a
  >       8|   bar = Bar.new
  >       9| end
  > =>#0	<main> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:1
  > s
  >
  > (rdbg:remote) s
[1, 9] in /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb
  >       1| module Foo
  > =>    2|   class Bar
  >       3|     def self.a
  >       4|       p "hello"
  >       5|     end
  >       6|   end
  >       7|   Bar.a
  >       8|   bar = Bar.new
  >       9| end
  > =>#0	<module:Foo> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:2
  >   #1	<main> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:1
  >
  > (rdbg:remote) s
[1, 9] in /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb
  >       1| module Foo
  >       2|   class Bar
  > =>    3|     def self.a
  >       4|       p "hello"
  >       5|     end
  >       6|   end
  >       7|   Bar.a
  >       8|   bar = Bar.new
  >       9| end
  > =>#0	<class:Bar> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:3
  >   #1	<module:Foo> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:2
  >   #2	<main> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:1
  >
  > (rdbg:remote) s
[2, 9] in /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb
  >       2|   class Bar
  >       3|     def self.a
  >       4|       p "hello"
  >       5|     end
  >       6|   end
  > =>    7|   Bar.a
  >       8|   bar = Bar.new
  >       9| end
  > =>#0	<module:Foo> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:7
  >   #1	<main> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:1
  > s
  >
  > (rdbg:remote) s
[1, 9] in /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb
  >       1| module Foo
  >       2|   class Bar
  >       3|     def self.a
  > =>    4|       p "hello"
  >       5|     end
  >       6|   end
  >       7|   Bar.a
  >       8|   bar = Bar.new
  >       9| end
  > =>#0	Foo::Bar.a at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:4
  >   #1	<module:Foo> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:7
  >   #2	<main> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:1
  > s
  >
  > (rdbg:remote) s
[1, 9] in /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb
  >       1| module Foo
  >       2|   class Bar
  >       3|     def self.a
  >       4|       p "hello"
  > =>    5|     end
  >       6|   end
  >       7|   Bar.a
  >       8|   bar = Bar.new
  >       9| end
  > =>#0	Foo::Bar.a at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:5 #=> "hello"
  >   #1	<module:Foo> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:7
  >   #2	<main> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:1
  > s
  >
  > (rdbg:remote) s
[3, 9] in /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb
  >       3|     def self.a
  >       4|       p "hello"
  >       5|     end
  >       6|   end
  >       7|   Bar.a
  > =>    8|   bar = Bar.new
  >       9| end
  > =>#0	<module:Foo> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:8
  >   #1	<main> at /var/folders/kv/w1k6nh1x5fl7vx47b2pd005w0000gn/T/debugger20210706-45047-efy1kk.rb:1

  [DEBUGGEE SESSION LOG]
  > EBUGGER: Debugger can attach via UNIX domain socket (/Users/naotto/.ruby-debug-sock/ruby-debug-naotto-45078)
  > DEBUGGER: wait for debuger connection...
  > DEBUGGER: Connected.
  > "hello"
   .
  <false> is not true.
/Users/naotto/workspace/debug/test/support/utils.rb:146:in `rescue in block in run_test_scenario'
/Users/naotto/workspace/debug/test/support/utils.rb:141:in `block in run_test_scenario'
/Users/naotto/workspace/debug/test/support/utils.rb:102:in `spawn'
/Users/naotto/workspace/debug/test/support/utils.rb:102:in `run_test_scenario'
/Users/naotto/workspace/debug/test/support/utils.rb:81:in `debug_on_unix_domain_socket'
/Users/naotto/workspace/debug/test/support/utils.rb:44:in `debug_code'
test/debug/foo_test.rb:22:in `test_foo'
     19:     end
     20:
     21:     def test_foo
  => 22:       debug_code(program) do
     23:         type 's'
     24:         type 's'
     25:         type 's'
```shell

[ono-max]

I need to change this part to output complete backlog(In the above example, this would be "hello") in remote deguggee.

[ko1]

it can raise EIO error, so you need to rescue it.

[ono-max]

Thanks!
I'll change it.

[ono-max]

https://github.com/ruby/debug/pull/132/files#diff-ee14bf65f14927f7778a246f90c5cec0c581be3e2658c2a8a3726c59db5be3f9R27