克林:Shift-Command-K对我来说很有用。

我把我的iPhone升级到最新的11.0.3版本，然后重启了我的iPhone。重启XCode 9。然后就成功了。

克林:Shift-Command-K对我来说很有用。

我拔掉了电缆，看到了这个。在它到达终点后，我能够毫无问题地运行它。

你不需要拔掉电源就能看到这个;只要点击取消，你就会看到它的进度。

我的设置

macOS 10.14.6 iOS 13.2.3 Xcode 11.2

在2019-11-24之前尝试了所有的“快速跑”技巧，但都没有成功。 等待似乎是不可避免的，但对我来说却异常漫长:

新升级的iOS版本。

然后我在reddit上找到了这条最有意义的评论:

This is required when you connect a device with an iOS version that the respective computer's Xcode didn't see before. It saves them in /Users/username/Library/Developer/Xcode/iOS DeviceSupport and it does take a while. Don't restart Xcode as it will not help you, just wait for it to finish. It takes quite some time because these debugger support files occupy a lot of space (29 GB for me), though you can safely delete any version from there, and if you connect a device with that version again, it will re-save it from scratch.

因此，如果你刚刚升级了iOS，那么“从头开始”的部分可能需要比平时更长的时间，这也取决于你的网络状况。就我而言，这绝对比其他人所说的“10-15分钟”要长得多。我用小时来计算。

很多技巧似乎都起作用了，但他们忽略了这样一个事实:当你尝试一些东西时，Xcode会在后台继续进行设置，并且很可能在你进行重启/重启循环时恢复它的工作。

这让我注意到我的Xcode版本只比iOS版本晚了一步。升级Xcode后，它开始工作了。

但是它花了更长的时间，因为我按照提示删除了iOS DeviceSupport文件夹!

以下是我的建议:

Check your Xcode version down to the minor version to make sure it should actually support the iOS version. Check your Mac's free disk space to make room for newly generated device support content under ~/Library/Developer/Xcode/iOS DeviceSupport as this tip suggested. Check if you have connected your device to a fast-enough USB port, as this tip suggests. Wait till Xcode finishes "preparing for debugging". If it doesn't finish in a few seconds or minutes, keep waiting. DO NOT remove any folder as some tips may suggest. Removal would simply make you wait longer!

在iPhone上:

设置>开发人员>清除可信计算机

等一下，就这些了。