Swift in GitHub Codespaces

[matthewruzzi]

Select Topic Area

Question

Body

What is the best way to use Swift in GitHub Codespaces? When I try to use the swift-devcontainer-template the codespaces take a very long time to build and can use a large amount of storage (15+ GB). I also sometimes get error messages when trying to use it.

[MasteraSnackin]

I've had the same experience with the swift-devcontainer-template - the build times are painfully slow and it eats up a ton of storage.

The issue is that template does a lot of heavy lifting during setup, which is great for a full-featured environment but overkill for most Swift projects.

Here's what actually works better:

1. Use a prebuilt Swift Docker image instead of the template. Something like swift:latest or a specific version like swift:5.9 from Docker Hub. This skips all the build steps since Swift is already installed.

2. Create a minimal .devcontainer/devcontainer.json:

{
  "image": "swift:latest",
  "customizations": {
    "vscode": {
      "extensions": ["sswg.swift-lang"]
    }
  }
}

3. If you need additional tools, use a simple Dockerfile that starts from a Swift image and just adds what you need, rather than building everything from scratch.

This approach typically starts up in under a minute and uses around 2-4 GB instead of 15+ GB. The Swift VS Code extension works perfectly with it, and you get full IntelliSense, debugging, and testing support.

Have you tried using a prebuilt image instead of the template?

[matthewruzzi]

The template is based on the prebuilt swift image but it adds a few features and extra configuration.

{
    "name": "Swift",
    "image": "swift:${templateOption:imageVariant}",
    "features": {
        "ghcr.io/devcontainers/features/common-utils:2": {
            "installZsh": "false",
            "username": "vscode",
            "upgradePackages": "false"
        },
        "ghcr.io/devcontainers/features/git:1": {
            "version": "os-provided",
            "ppa": "false"
        }
    },
    "runArgs": [
        "--cap-add=SYS_PTRACE",
        "--security-opt",
        "seccomp=unconfined"
    ],
    // Configure tool-specific properties.
    "customizations": {
        // Configure properties specific to VS Code.
        "vscode": {
            // Set *default* container specific settings.json values on container create.
            "settings": {
                "lldb.library": "/usr/lib/liblldb.so"
            },
            // Add the IDs of extensions you want installed when the container is created.
            "extensions": [
                "swiftlang.swift-vscode"
            ]
        }
    },
    // Use 'forwardPorts' to make a list of ports inside the container available locally.
    // "forwardPorts": [],

    // Set `remoteUser` to `root` to connect as root instead. More info: https://aka.ms/vscode-remote/containers/non-root.
    "remoteUser": "vscode"
}

[github-actions[bot]]

🕒 Discussion Activity Reminder 🕒

This Discussion has been labeled as dormant by an automated system for having no activity in the last 60 days. Please consider one the following actions:

1️⃣ Close as Out of Date: If the topic is no longer relevant, close the Discussion as out of date at the bottom of the page.

2️⃣ Provide More Information: Share additional details or context — or let the community know if you've found a solution on your own.

3️⃣ Mark a Reply as Answer: If your question has been answered by a reply, mark the most helpful reply as the solution.

Note: This dormant notification will only apply to Discussions with the Question label. To learn more, see our recent announcement.

Thank you for helping bring this Discussion to a resolution! 💬