"Improve native Apple build and test compatibility"

Once handles more existing Xcode projects and Swift packages without changing their sources or delegating compilation to Xcode.

Swift packages use single-worker batch compilation by default, avoiding repeated frontend startup and parsing for each source file. Whole-module optimization and explicit package compiler flag overrides remain supported.

Swift package dependency resources are installed in the macOS test bundle's resources directory, and generated Bundle.module accessors find them there. Package C and C++ targets honor conditional header search paths.

Frameworks that import XCTest receive its Swift overlay search path. Objective-C-only test bundles link through Clang, avoiding unnecessary Swift runtime compatibility libraries. Swift compilation and linking no longer load those libraries twice when a target requests all archive members.

Embedded framework signing preserves versioned macOS layouts instead of creating a signature directory at the framework root. Resource bundles and help books also retain their complete directory trees. Synchronized groups preserve explicit resource folders and include web resources and scripting dictionaries. AppleScript sources compile into .scpt resources.

Explicit macOS CODE_SIGNING_ALLOWED=NO configurations omit entitlement-bearing signing while retaining an ad-hoc bundle seal for local integrity checks. Capabilities that require authorized signing remain disabled in this mode.

Xcode imports accept build phase scripts stored as arrays of lines, normalize relative script paths, and resolve package tool dependencies declared through target dependencies. Linked framework dependency matching also handles spaces in target names. Scripts receive transitive framework products and selected developer and toolchain paths.

Swift builds honor native regular-expression and concurrency defaults. String catalogs compile into localized runtime resources and generate Swift symbols when the target enables them. Application-hosted macOS tests use Xcode's test runner without asking Xcode to build the products.

Test execution uses each scheme's default plan instead of combining exclusions and arguments from its alternative plans.

Test discovery preserves the enclosing suite across nested helper types, comments, strings, and local declarations, preventing duplicate test identities from corrupting the reported results. Source discovery does not imply execution: tests without an observed result remain unknown.