Cannot interrupt program execution from remote control interface

[izaera]

After sending PR #238 to fix remote debugging, I still cannot interrupt program execution from the remote control interface.

I'm starting a simple Ruby script that loops forever with a 5 second delay per loop and a calls 'puts' with the loop count. I run it with remote byebug and I connect to the debugging remote and control ports. Everything looks fine, but when I issue an interrupt command in the control port while the program is running, it replies that Byebug has not been started yet.

I'm not sure what this means. If it cannot be fixed now, any hint on how to continue diagnosing/fixing this will be appreciated.

Thanks in advance.

[deivid-rodriguez]

@izaera Thanks for the report and sorry for not replying to your emails soon enough, I don't have a lot of time for this... :(

Unfortunately, remote debugging (and thus integrations) are currently the weakest part of byebug. It was ported from original debugger, but it has only minimal tests and I haven't really never used it, so it's been always mantained by the community from the beginning.

One question, does remote debugging work properly and is it only the interrupt command failing?

Regards!

[izaera]

Hi David: Don't worry about response times. I know what being busy is :-). Regarding your question: everything seems to work fine but the interrupt command. Again, I may help with the fix if I get some orientation on how to proceed (because I'm not an expert in Ruby internals :-( ). Cheers.

[izaera]

Just a hint: the problem seems to be an exception when Byebug.thread_context is called in:

https://github.com/deivid-rodriguez/byebug/blob/master/lib/byebug/commands/interrupt.rb#L27

AFAIK, that is a native method so I had to stop debugging there. I may try to add some traces to the native code, but I have to setup a proper compilation environment, so I have to get some spare time.

[izaera]

More info about this. Behaviour has changed after #242

Using the code from that PR in local as my byebug gem, I have done the following:

1. Start the following script:

#!/usr/bin/env ruby
require 'byebug'
require 'byebug/core'
Byebug.wait_connection = true
Byebug.start_server('localhost', 1234)

i = 0
loop do
  puts i
  i += 1
  sleep 2
end

2. Connect with telnet to control port (1235) -> I get the PROMPT (ctrl)
3. Connect with telnet to remote port (1234) -> The program starts
4. Type interrupt + CR in control port -> the program pauses and I get the PROMPT (byebug) in remote port
5. Type continue in remote port -> the program restarts
6. Type interrupt + CR in control port -> I get the reported error

So I can interrupt the program just once. Before my PR -or some other change I'm not aware of- I couldn't even interrupt the program once.

[angelovAlex]

The same issue happens to me :( Very sad that there's no normal way to debug ruby code.. seems like ruby is not a good solution for new projects

[deivid-rodriguez]

@izaera I'm pretty sure you no longer use ruby, but I'm letting you know that this should be fixed by #406, just in case!

[angelovAlex]

Glad to hear it. I never stop to use ruby, as it's still my favorite. I was in bad mood when I wrote last comment, as I was writing a gui for the debugger and had to stop the project because of this bug.

[deivid-rodriguez]

@angelovAlex Glad to hear that you still use Ruby! Maybe you can resume your work on that GUI now 😄

[izaera]

@deivid-rodriguez Yes, you are right: I don't use Ruby any more because I changed job. However, my Atom debugger was half developed so, if anyone wants to continue it, he/she is welcome. Thx for the info :-).

[deivid-rodriguez]

Thanks for the heads-up, @izaera! :)