After upgrade to 1.27.0 multitheaded debugging brakes on "paused on pause"

[egorse]

Environment data

• VS Code version: 1.27.0
• Extension version: 2018.8.0
• OS and version: Ubuntu 14.04.5 LTS (Ubuntu 16.04.5 LTS)
• Python version: 2.7.6 (2.7.12)
• Type of virtual environment used: N/A
• Relevant/affected Python packages and their versions: N/A

Actual behavior

When debugging multi-threaded app, the placing breakpoint in some thread cause break there, but very soon it breaks in different threads, jumps to the place and expand thread's stack which has "Paused on pause" status.

Expected behavior

After stopping at breakpoint stay there - not to switch to others threads nor expand stack on "paused on pause".

Steps to reproduce:

Run under debugger next app with break at print 'th1'. Watch break position is jumping to "paused on pause" threads.

import threading
import time

class RunThread(threading.Thread):
    kind = 'Thread'
    def __init__(self, name, fn, args = ()):
        threading.Thread.__init__(self)
        self.name = name
        self.fn   = fn
        self.args = args
        self.start()
    def run(self):
        self.fn(*(self.args))

def th1():
    while True:
        print 'th1'
        time.sleep(5)

def th2():
    while True:
        print 'th2'
        time.sleep(10)

def th3():
    while True:
        print 'th3'
        time.sleep(15)

def main():
    threads = []
    threads.append(RunThread("aaa", th1))
    threads.append(RunThread("bbb", th2))
    threads.append(RunThread("ccc", th3))

    for t in threads:
        t.join()

if __name__ == '__main__':
    main()

[brettcannon]

Please verify if this is a bug, @d3r3kk .

[primes2h]

It seems to be a regression in ms-python extension.

I downgraded to 2018.7.1 version and it works as expected.

Similar issues #2520 and #2521

[DonJayamanne]

cc @karthiknadig. FYI - we're yet to verify this issue.

[karthiknadig]

This is microsoft/ptvsd#777

[DonJayamanne]

@karthiknadig @brettcannon

• Thanks, I guess this means we'll need a new release of PTVSD for this fix.
• We'll need a new release of the extension as well.

[DonJayamanne]

Changing the status to P1, as this is something that can be resolved in the next release with a new version of PTVSD.

[egorse]

As @primes2h said - previous version https://marketplace.visualstudio.com/_apis/public/gallery/publishers/ms-python/vsextensions/python/2018.7.1/vspackage works just fine.

Just for those who looks for fast solution curl -O -J -L https://marketplace.visualstudio.com/_apis/public/gallery/publishers/ms-python/vsextensions/python/2018.7.1/vspackage && code --install-extension ms-python.python-2018.7.1.vsix

[DonJayamanne]

@egorse
Please could you download our latest development version of the extension and let us know whether this fixes your issue? Instructions are simple and can be found here. Basically just download our dev version of the vsix file and install it.

[egorse]

@DonJayamanne tried with 1.27.2 and the fresh dev plugin. There is no more switches to "paused on pause" threads and debugger keep "focus" at proper thread. So debugging experience is back to normal.
Minor cosmetic note - the stack for last thread in list always get expanded - even if you explicitly collapse it and break is on one of previous thread.

[MandarJKulkarni]

@DonJayamanne @veuncent
Raised #2698.

[DonJayamanne]

@egorse
Thanks, I'll close this issue as it has been resolved and you've been kind enough to validate it.
Please do create a separate GitHub issue for the cosmetic issue you encountered