问题
According to this guide, there should be an App Sandbox capability in the project file:
However, for some reason my app project does not have any App Sandbox capability that I can turn on:
Why is it missing, and how can I get it there?
回答1:
First of all, you should open the ***.entitlements file. In this file, add a Key named App Sandbox and changed Value to YES.
After completing the above steps, click command + b then go back to Signing & Capabilities, the App Sandbox will appear.
回答2:
If your Apple provisioning profile is missing the App Sandbox entitlement then it won't show up in xcode.
FYI - you can add manually to entitlement file, however it wont let you build unless described in your provisioning profile. Same goes for ditribution as well.
You can regenrate the provisioning profile with the desired capabilities, if you are the admin/team agent of the Apple store project.
hope this helps.
来源：https://stackoverflow.com/questions/55346223/app-sandbox-capability-missing-in-xcode-project