Remove swiftSettings that cause errors when building as a dependency in Xcode

[rgoldberg]

Remove swiftSettings that cause errors when building as a dependency in Xcode.

Resolve #108

[gemini-code-assist]

Summary of Changes

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This pull request enhances the compatibility of the Swift package by removing problematic swiftSettings that previously led to build failures when the package was consumed as a dependency in Xcode. The change aims to streamline the integration process for other projects and resolve a known issue, ensuring a smoother development experience for users of this package.

Highlights

• Build Compatibility Fix: Removed specific swiftSettings from Package.swift that were causing build errors when this package was integrated as a dependency within Xcode projects.
• Issue Resolution: This change directly resolves issue Conflicting options '-Werror' and '-suppress-warnings' build error when using as a dependency in Xcode 26.3 on macOS 26.3.1 #108, which reported the build failures due to these settings.
• Removed Swift Settings: The removed settings include .enableUpcomingFeature("ExistentialAny") and .treatWarning for ExistentialAny and MutableGlobalVariable.

Changelog

• Package.swift
  • Removed custom swiftSettings that caused build errors when the package was used as a dependency in Xcode.

Activity

• No human activity has been recorded on this pull request yet.

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[gemini-code-assist]

Code Review

This pull request removes swiftSettings from Package.swift to resolve build errors when this package is used as a dependency. My review includes a suggestion to conditionally apply these settings. This would preserve the strict checks for local development while still fixing the issue for consumers of the package.

I am having trouble creating individual review comments. Click here to see my feedback.

Package.swift (88-104)

While removing these Swift settings fixes the build errors for consumers of this package, it also removes valuable checks for the development of the package itself. These settings help enforce modern Swift practices and prevent certain types of warnings.

A better approach could be to apply these settings conditionally, so they are used during local development and CI, but not when the package is used as a dependency. This can be achieved using an environment variable.

For example, you could modify your Package.swift like this:

// At the top of Package.swift
import PackageDescription
import Foundation

// Check for a development environment variable
let isDevelopment = ProcessInfo.processInfo.environment["DEVELOPMENT"] != nil

let swiftSettings: [SwiftSetting] = isDevelopment ? [
    .enableUpcomingFeature("ExistentialAny"),
    .treatWarning("ExistentialAny", as: .error),
    .treatWarning("MutableGlobalVariable", as: .error),
] : []

// Then, for each relevant target:
.target(
    name: "SomeTarget",
    dependencies: [...],
    swiftSettings: swiftSettings
),

This way, you can run DEVELOPMENT=1 swift build to build with the strict settings, while regular users of your package won't be affected. This would allow you to keep the benefits of these checks without impacting downstream users.

[tayloraswift]

superseded by #112