PackagePlugin's PackageManager.getSymbolGraph does not support binaryTarget

[Kyle-Ye]

Is it reproducible with SwiftPM command-line tools: swift build, swift test, swift package etc?

• Confirmed reproduction steps with SwiftPM CLI.

Description

Background Context: SwiftPackageIndex/SwiftPackageIndex-Server#3061 (comment)

If a target has a dependency on binaryTarget. Then the call of PackageManager.getSymbolGraph to that target will get a directory contains no symbol graph.

It will break PackageManager.getSymbolGraph's client such as swift-docc-plugin.

The downstream user can generate doc using swift build and call docc convert to generate documentation. But if they migrate to swift-docc-plugin or swift-docc-plugin based service like SwiftPackageIndex, the documentation build will fail.

// ✅ Build Package Documentation via Xcode GUI

// ✅ Build Package Documentation manually
swift build --target DemoKit \
  -Xswiftc -emit-symbol-graph \
  -Xswiftc -emit-symbol-graph-dir -Xswiftc "./symbol-graph"

docc convert --additional-symbol-graph-dir ./symbol-graph ...

// ❌ Build Package Documentation via swift-docc-plugin
swift package generate-documentation --target DemoKit

Expected behavior

Produce SymbolGraph normally.

Actual behavior

Call swift-symbolgraph-extract with the arguments manually in terminal or adding the following patch to SymbolGraphExtract.swift

    public func extractSymbolGraph(
        ...
        try process.launch()
-       try process.waitUntilExit()
+       let result = try process.waitUntilExit()
+       if let error = String(bytes: try result.stderrOutput.get(), encoding: .utf8) {
+            print(error)
+.      }
    }

And you will get the following error message.

"<unknown>:0: error: missing required module \'MMKV\'\nError: Failed to load the module \'DemoKit\'. Are you missing build dependencies or include/framework directories?\nSee the previous error messages for details. Aborting.\n"

I have tried to add the framework manually via -F/-I/-L ${MMKV_framework_path} but none of them will work.

Steps to reproduce

For user side reproduce steps:

1. Download the following DemoKit.zip package
2. Run swift package generate-documentation --target DemoKit --verbose and no documentation will be created.

For swiftpm developer reproduce steps:

1. Set up swiftpm repo development environment
2. Build PackageDescription target first and then choose swift-package target
3. Set working directory to DemoKit and the corresponding arguments on launch in Xcode
   4.(Optional) Apply the diff mentioned above.

DemoKit.zip

Note: Here I use MMKV.xcframework as an example but any binary framework would have the same issue. The binary framework have nothing special here.

Swift Package Manager version/commit hash

5.10

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

5.10 & macOS 14.4.1

[Kyle-Ye]

Is this an expected unimplemented feature or a bug we should fix? Checking the repository's Git history, I believe @MaxDesiatov would have some insights on this scope. Could you help give a look at this? Thanks