Plugin sandbox issue regressed on 5.9

[Kyle-Ye]

Description

Originally tracked on SwiftGen/SwiftGenPlugin#14

Expected behavior

The Package continue to compile on Swift 5.9

Actual behavior

The Package fail to compile on Xcode 15 Beta 5/Swift 5.9 (Plug-in ended with non-zero exit code: 1) while can compile on Xcode 14.3.1/Swift 5.8

Steps to reproduce

1. Download the DemoKit.zip, unzip it and cd into DemoKit.
2. Run swift-build.
   DemoKit.zip

Swift Package Manager version/commit hash

release/5.9.0 - 3cc9fae

Swift & OS version (output of swift --version ; uname -a)

swift-driver version: 1.87.1 Apple Swift version 5.9 (swiftlang-5.9.0.128.2 clang-1500.0.40.1)
Target: arm64-apple-macosx14.0
Darwin 23.0.0 Darwin Kernel Version 23.0.0: Tue Aug 1 03:25:51 PDT 2023; root:xnu-10002.0.242.0.6~31/RELEASE_ARM64_T6000 arm64

Xcode 15 Beta 6 and macOS 14 Beta 5

[neonichu]

If this ever worked, that was a bug. The plugin needs to ask for permission to write to the working directory via the capabilities API or it needs to write to the directory provided to it via the plugin context.

[Kyle-Ye]

Got it. Thanks for the clarification.

buildTool currently does not support writeToPackageDirectory permission. Maybe in such case, we should consider using a plugin with command capability.