[dev containers] Activating Swift extension failed: Cannot read properties of null (reading 'replace')

[MahdiBM]

Describe the bug
Activating Swift extension failed: Cannot read properties of null (reading 'replace')

To Reproduce
Steps to reproduce the behavior:
Clone https://github.com/MahdiBM/swift-dns.
checkout vscode-ext-dev-cont-active-failed.
Open the project in a the project's dev container.

Expected behavior
No activation failure.

Environment

• OS: [e.g. Ubuntu 20.04] macOS 26
• Swift version (output of swift --version): 6.2 nightlies
• Visual Studio Code version: 1.92.6; Cursor 1.0.0
• vscode-swift version: 2.4.0

Additional context
I think I saw this problem when i was on macOS 15.4 as well, so shouldn't be macOS/Xcode 26 related. It's in a dev container anyway.

[award999]

hey @MahdiBM the issue is you explicitly set the swift.path setting in the devcontainer.json file to null which is different in typescript that undefined. When getting the setting vscode treats it as an explicitly null value. So set the setting to undefined or "" in your config to get the behaviour you're probably looking for. Now I will throw up a quick patch so it doesn't fail activation so horribly

[matthewbastien]

Verified with a3a18c5.