ifwe'reintherealprecommithandlerwecan'tactuallyaddanynewfencesdue

&＃8212;&＃8211; “[App] if we&＃8217;re in the real pre-commit handler we can&＃8217;t actually add any new fences due ”

翻译：

&＃8212;&＃8211;“[应用]如果我们在真实预提交处理我们不能添加任何新的围栏，由于CA限购”

才知道这个问题其实是xcode 编译器设置的问题，其实并不影响app使用:

&＃8220;&＃8212;&＃8212;-it comes from +[UIWindow _synchronizeDrawingAcrossProcessesOverPort:withPreCommitHandler:] via os_log API. It doesn&＃8217;t depend from another components/frameworks that you are using(only from UIKit) &＃8211; it reproduces in clean single view application project on changing interface orientation.

This method consists from 2 parts:

adding passed precommit handler to list of handlers;

do some work, that depends on current finite state machine state.

When second part fails (looks like prohibited transition), it prints message above to error log. However, I think that this problem is not fatal: there are 2 additional assert cases in this method, that will lead to crash in debug.&＃8212;&＃8220;

翻译：

&＃8212;-它来自+ [ UIWindow _synchronizedrawingacrossprocessesoverport：withprecommithandler：]通过os_log API。它不取决于另一个组件/框架，您使用的是（从UIKit）-再现清洁单视图应用程序项目改变界面取向。

该方法由2部分组成：

并通过预提交处理程序处理程序列表；

做一些工作，这取决于当前的有限状态机状态。

当第二部分失败（看起来像被禁止的过渡）时，它将上面的消息打印到错误日志上。然而，我认为这个问题不是致命的：有2个额外的断言在这种方法的情况下，这将导致崩溃在调试

解决方法：

in your Xcode:

Click on your active scheme name right next to the Stop button

Click on Edit Scheme&＃8230;.

in Run (Debug) select the Arguments tab

in Environment Variables click +

add variable: OS_ACTIVITY_MODE = disable

其实这好像是老版xcode 的，

其实点击Xcode的product就可以找到（OS_ACTIVITY_MODE是name,disable 是值）

（特别注意：标注为disable失效后，程序可能会运行失败！）