Can't use package with traits disabled.

[Cyberbeni]

Linux Mint 22.2, Swift 6.2.3

Project: https://github.com/Cyberbeni/auth.home.arpa/tree/12831fccf5e953b62ae668bcf138c40c0dea92cf

Changes:

diff --git a/Package.swift b/Package.swift
index 1d0aab5..fd45e91 100644
--- a/Package.swift
+++ b/Package.swift
@@ -22,7 +22,7 @@ let package = Package(
        ],
        dependencies: [
                .package(url: "https://github.com/Cyberbeni/CBLogging", from: "1.3.1"),
-               .package(url: "https://github.com/hummingbird-project/hummingbird", from: "2.18.3"),
+               .package(url: "https://github.com/hummingbird-project/hummingbird", from: "2.19.0", traits: []),
                .package(url: "https://github.com/hummingbird-community/hummingbird-elementary", from: "0.4.2"),
                .package(url: "https://github.com/sliemeobn/elementary-htmx", from: "0.5.1"),
                // Plugins:

(This also makes Package.resolved update, which will sometimes include swift-configuration, sometimes not.)

Running swift build produces this error:

error: 'hummingbird': product 'Configuration' required by package 'hummingbird' target 'HummingbirdTLS' not found in package 'swift-configuration'.
error: ExitCode(rawValue: 1)
[0/1] Planning build

edit: I retried it with also updating the version (already reflected in the code above) and the first build succeeded but subsequent incremental builds failed with the same error.

[adam-fowler]

Damn can't believe we missed this one.

[Cyberbeni]

Seems like it's caused by the hummingbird-elementary package also depending on hummingbird and SPM getting confused whether it should use the default traits based on that dependency chain or the traits that I defined.

[adam-fowler]

Oh god. So is this a SwiftPM issue! I'll have a closer look tomorrow or Monday just to make sure I've not made a mistake somewhere. The introduction of traits has just been a complete pain.

[adam-fowler]

I think this issue is related to https://forums.swift.org/t/adding-trait-to-library-causing-error-in-projects-dependent-on-library/83730 where including traits and multiple Package.swift files cause issues.

As far as I can tell swift-configuration only uses Foundation if the JSON trait is enabled (which happens to be a default annoyingly).

[sliemeobn]

interesting, I guess that would mean I'd have to use traits: [] in the elementary-hummingbird dependency, right? would that then be a breaking change too?

[adam-fowler]

interesting, I guess that would mean I'd have to use traits: [] in the elementary-hummingbird dependency, right? would that then be a breaking change too?

I've disabled the JSON trait in swift-configuration so there is less reason to disable configuration for hummingbird now. But if you do decide to go ahead with that, please verify it doesn't break any packages that depend on hummingbird-elementary that either enable/disable the ConfigurationSupport trait in Hummingbird.

[adam-fowler]

This appears to be fixed with the current Swift 6.3 snapshot