fetch-package fails on windows ever since moving to async fetch

fetch-package completes, and then at the end, it prints the following exception:

Traceback (most recent call last):
  File "cerbero-uninstalled", line 9, in <module>
    main()
  File "d:\projects\cerbero\autotools\master\cerbero\main.py", line 190, in main
    Main(sys.argv[1:])
  File "d:\projects\cerbero\autotools\master\cerbero\main.py", line 60, in __init__
    self.run_command()
  File "d:\projects\cerbero\autotools\master\cerbero\main.py", line 159, in run_command
    res = commands.run(command, self.config, self.args)
  File "d:\projects\cerbero\autotools\master\cerbero\commands\__init__.py", line 78, in run
    return _commands[command].run(config, args)
  File "d:\projects\cerbero\autotools\master\cerbero\commands\fetch.py", line 143, in run
    args.print_only, args.jobs)
  File "d:\projects\cerbero\autotools\master\cerbero\commands\fetch.py", line 96, in fetch
    run_until_complete(tasks)
  File "d:\projects\cerbero\autotools\master\cerbero\utils\__init__.py", line 536, in run_until_complete
    loop.run_until_complete(asyncio.gather(*tasks))
  File "c:\Python37\lib\asyncio\base_events.py", line 573, in run_until_complete
    return future.result()
  File "d:\projects\cerbero\autotools\master\cerbero\build\recipe.py", line 82, in async_wrapped
    await stepfunc()
  File "d:\projects\cerbero\autotools\master\cerbero\build\source.py", line 315, in fetch
    await git.fetch(self.repo_dir, fail=False, logfile=get_logfile(self))
  File "d:\projects\cerbero\autotools\master\cerbero\utils\git.py", line 134, in fetch
    return await shell.async_call(cmd, git_dir, fail, logfile=logfile, cpu_bound=False)
  File "d:\projects\cerbero\autotools\master\cerbero\utils\shell.py", line 227, in async_call
    async with semaphore:
  File "c:\Python37\lib\asyncio\locks.py", line 92, in __aenter__
    await self.acquire()
  File "c:\Python37\lib\asyncio\locks.py", line 474, in acquire
    await fut
RuntimeError: Task <Task pending coro=<log_step_output.<locals>.async_wrapped() running at d:\projects\cerbero\autotools\master\cerbero\build\recipe.py:82> cb=[gather.<locals>._done_callback() at c:\Python37\lib\asyncio\tasks.py:664]> got Future <Future pending> attached to a different loop

CC: @pamarcos