在使用vnpy 3.4.0进行策略回测时发现一个问题，后使用系统自带的示例策略 KingKeltnerStrategy 也可以再现。
一，问题描述 在进行回测时 2022-10-12 的数据会重复执行，其他日期则不会。
2022-10-12的数据回测完成后，会再回测一次。5分钟bar的输出日志如下 ：

二， 回测设置如下
1， 在示例策略 KingKeltnerStrategy中

增加最后一行bar输出： print('\n\n', bar.datetime, ' 分钟线bar为： ' , str(bar))

2，设置回测参数如下

3，运行回测后，就会出现开头 5分钟bar的输出日志 所描述的问题。

请帮忙分析解决，谢谢！

因为需要调试和分析回测数据， 回测时把 log.level 设定为10， 单日志文件 vt_20201027.log 还是为空。
请问如何解决，非常感谢！

在centos安装vnpy，执行bash install.sh 时报错，请问如何解决，谢谢

wget https://pip.vnpy.com/colletion/ta-lib-0.4.0-src.tar.gz
--2020-10-12 13:23:57-- https://pip.vnpy.com/colletion/ta-lib-0.4.0-src.tar.gz
正在解析主机 pip.vnpy.com (pip.vnpy.com)... 125.37.206.219
正在连接 pip.vnpy.com (pip.vnpy.com)|125.37.206.219|:443... 已连接。
已发出 HTTP 请求，正在等待回应... 404 Not Found
2020-10-12 13:23:58 错误 404：Not Found。

以命令方式执行多进程优化的时候，报以下错误，请问如何解决：

2020-10-09 16:52:59.924560 开始加载历史数据
2020-10-09 16:53:00.023296 加载进度：########## [100%]
2020-10-09 16:53:00.023296 历史数据加载完成，数据量：41761
2020-10-09 16:53:00.322496 开始加载历史数据
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "D:\vnstudio\lib\multiprocessing\spawn.py", line 105, in spawn_main
exitcode = _main(fd)
File "D:\vnstudio\lib\multiprocessing\spawn.py", line 114, in _main
prepare(preparation_data)
File "D:\vnstudio\lib\multiprocessing\spawn.py", line 225, in prepare
_fixup_main_from_path(data['init_main_from_path'])
File "D:\vnstudio\lib\multiprocessing\spawn.py", line 277, in _fixup_main_from_path
run_name="mp_main")
File "D:\vnstudio\lib\runpy.py", line 263, in run_path
pkg_name=pkg_name, script_name=fname)
File "D:\vnstudio\lib\runpy.py", line 96, in _run_module_code
mod_name, mod_spec, pkg_name, script_name)
File "D:\vnstudio\lib\runpy.py", line 85, in _run_code
exec(code, run_globals)
File "D:\Pycharm\vnpy-master\vnpy\app\cta_strategy\backtesting\backtesting_demo_multiprocess.py", line 53, in <module>
engine.run_optimization(setting)
File "D:\Pycharm\vnpy-master\vnpy\app\cta_strategy\backtesting.py", line 578, in run_optimization
pool = ctx.Pool(multiprocessing.cpu_count())
File "D:\vnstudio\lib\multiprocessing\context.py", line 119, in Pool
context=self.get_context())
File "D:\vnstudio\lib\multiprocessing\pool.py", line 177, in init
self._repopulate_pool()
File "D:\vnstudio\lib\multiprocessing\pool.py", line 238, in _repopulate_pool
self._wrap_exception)
File "D:\vnstudio\lib\multiprocessing\pool.py", line 257, in _repopulate_pool_static
w.start()
File "D:\vnstudio\lib\multiprocessing\process.py", line 112, in start
self._popen = self._Popen(self)
File "D:\vnstudio\lib\multiprocessing\context.py", line 322, in _Popen
return Popen(process_obj)
File "D:\vnstudio\lib\multiprocessing\popen_spawn_win32.py", line 33, in init
prep_data = spawn.get_preparation_data(process_obj._name)
File "D:\vnstudio\lib\multiprocessing\spawn.py", line 143, in get_preparation_data
_check_not_importing_main()
File "D:\vnstudio\lib\multiprocessing\spawn.py", line 136, in _check_not_importing_main
is not going to be frozen to produce an executable.''')
RuntimeError:
An attempt has been made to start a new process before the
current process has finished its bootstrapping phase.

    This probably means that you are not using fork to start your
    child processes and you have forgotten to use the proper idiom
    in the main module:

        if __name__ == '__main__':
            freeze_support()
            ...

    The "freeze_support()" line can be omitted if the program
    is not going to be frozen to produce an executable.