Perception library fails compilation on CI but runs fine on local machine

[cabeca]

Hello,

We recently added swift-sharing to our project and it runs fine on my machine. But when we run the project on CI, the compilation fails with this error:

Testing failed:
	'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
	'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
	'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
	'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
	Testing cancelled because the build failed.

** TEST FAILED **

The strangest part is that it fails compiling swift-perception itself:

Error: 'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
    public var projectedValue: Bindable<Value> {
                               ^~~~~~~~
Error: 'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
    public init(projectedValue: Bindable<Value>) where Value: AnyObject & Perceptible {
                                ^~~~~~~~
Error: 'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
  extension Bindable: Identifiable where Value: Identifiable {
            ^~~~~~~~
Error: 'Bindable' is unavailable in iOS: Use @Bindable without the 'Perception.' prefix.
  extension Bindable: Sendable where Value: Sendable {}
            ^~~~~~~~

We have a minimum deployment target of iOS 17, so we should not even be using Perception while using the Sharing library.

Any pointers to help debug this?

[mbrandonw]

Hi @cabeca, thanks for sharing this. Can you get all the details of your CI and see if anything differs with your local environment? And a repro of this would be nice to have for us to investigate more deeply.

[cabeca]

I've been trying to figure out any relevant difference between my machine and the CI configuration with a colleague, but we had no luck today. We just cannot reproduce this on our local machines. We will continue the investigation tomorrow.

Any clues to what could cause this error while compiling swift-perception ? Swift compiler version? Missing minimum target somewhere? Warnings being treated as errors?

[mbrandonw]

The errors you have posted are pointing to a property of a type that is marked as unavailable on iOS 17+:

swift-perception/Sources/PerceptionCore/Bindable.swift

Lines 8 to 15 in 7efae79

	@available(iOS, introduced: 13, obsoleted: 17, message: "Use @Bindable without the 'Perception.' prefix.")
	@available(macOS, introduced: 10.15, obsoleted: 14, message: "Use @Bindable without the 'Perception.' prefix.")
	@available(tvOS, introduced: 13, obsoleted: 17, message: "Use @Bindable without the 'Perception.' prefix.")
	@available(watchOS, introduced: 6, obsoleted: 10, message: "Use @Bindable without the 'Perception.' prefix.")
	@available(visionOS, unavailable)
	@dynamicMemberLookup
	@propertyWrapper
	public struct Bindable<Value> {

It should not be necessary to repeat those @available annotations on every property, but you could try forking the library and adding that to each line that is pointed out in the error to see if it helps.

[cabeca]

Thank you for the tip. I have tried your suggestion today, but as I added more and more annotations, the error just shifted to other lines until eventually I ran out of properties to annotate. So that did not solve it.

I'll keep trying to figure out why our CI behaves differently from my local machine and will (hopefully) post my findings here.

[cabeca]

Hello.

I have managed to reproduce this error on my machine by running xcodebuild on the CLI with the same arguments used by CI.
Some extra information comes out of the build:

The following build commands failed:
	SwiftEmitModule normal arm64 Emitting\ module\ for\ PerceptionCore (in target 'PerceptionCore' from project 'swift-perception')
	EmitSwiftModule normal arm64 (in target 'PerceptionCore' from project 'swift-perception')

But the whole project compiles fine if I do it in Xcode! Maddening!

I then tried to make a new project with the same package organization as our big project, and tried to run the same command line build as above, but it compiles fine this time. So the problem must be with either our project settings, or our package combination. But then again, why does it compile fine in Xcode?

I'm at a lost on how to further debug this problem.

[cabeca]

@mbrandonw Is there a way for the swift-sharing library to not use swift-perception at all if the minimum deploy target is iOS 17, like in our case? I just want to use swift-sharing, but I'm having this problem with swift-perception compiling in our CI machines when in the end we will not even use it.

[cabeca]

After many, many hours of debugging, I finally figured out why I was having this compilation problem on CI.
We use .xcconfig files for our project, and one of the files had defined the following:

IPHONEOS_DEPLOYMENT_TARGET = 17.0

This causes the problem stated above.
I removed this configuration from the .xcconfig file, and added it to the main .xcodeproj file instead, and that fixes the problem.