Helps Flipper connect to physical iOS devices more reliably.

idb-workaround.py

#!/usr/bin/env python3

# See https://github.com/facebook/flipper/issues/262

import os
import sys
import syslog
import shlex
import time
import subprocess

idb_command_args = ['idb'] + sys.argv[1:]
idb_command_str = ' '.join([shlex.quote(arg) for arg in idb_command_args])

def main():
    udid = None
    is_file_command = False
    i = 1
    while i < len(sys.argv):
        if sys.argv[i] == '--udid':
            # Save udid
            i = i + 1
            udid = sys.argv[i]
        elif sys.argv[i][:2] == '--':
            # Ignore other flag arg
            i = i + 1
        elif sys.argv[i] == 'file':
            # This needs our help
            is_file_command = True
        i = i + 1
    if is_file_command:
        return run_with_workarounds(udid)
    else:
        return os.system(idb_command_str)

def run_with_timeout(timeout_secs, command_args):
    p = subprocess.Popen(command_args)
    try:
        p.wait(timeout_secs)
        return p.returncode
    except subprocess.TimeoutExpired:
        p.kill()
        return 1

def run_with_workarounds(udid):
    code = run_with_timeout(2, idb_command_args)
    if code == 0:
        return code
    syslog.syslog(syslog.LOG_ALERT, "idb-workaround Failed attempt 1/4")

    # Attempt 'connect' and try again.
    # This usually solves the problem.
    os.system('idb connect ' + shlex.quote(udid))
    code = run_with_timeout(2, idb_command_args)
    if code == 0:
        return code
    syslog.syslog(syslog.LOG_ALERT, "idb-workaround Failed attempt 2/4")

    # Wait an arbitrary amount of time before trying again.
    # This rarely solves the problem, but patience is a virtue.
    time.sleep(3)
    code = run_with_timeout(5, idb_command_args)
    if code == 0:
        return code
    syslog.syslog(syslog.LOG_ALERT, "idb-workaround Failed attempt 3/4")

    # Running `idb connect` will spawn many idb_companion instances, and after a certain number it will refuse to spawn
    # any more.  `idb disconnect` doesn't seem to help, so the only solution is to kill them all.
    os.system('idb kill')
    os.system('idb connect ' + shlex.quote(udid))
    code = run_with_timeout(10, idb_command_args)
    if code != 0:
        syslog.syslog(syslog.LOG_ALERT, "idb-workaround Failed attempt 4/4")
    return code

if __name__ == '__main__':
    code = main()
    # Exit with actual code, unless it's 256 or 512 because Python doesn't pass that on!
    sys.exit(code if code != 256 and code != 512 else 1)