After a refactoring, my project doesn't run anymore, but if I transfer the code from the library to the project, the project can compile normally. Spent a lot of time tracking down the problem and finally found the problem.
For this, I created a test project to reproduce the issue. This project has two Packages, DataMoodule and ProtocolModule, and two Apps, TestCrossModule and TestWholeModule. TestCrossModule is used to reproduce compilation errors. TestWholeModule is a project that can be compiled (same code as TestCrossModule, but there are no modules)
DataModule contains the following code:
// Protocol.swift
public protocol Anchor: CALayer {
associatedtype P: AnchorPath where P.A == Self
var path: P { get }
}
public protocol AnchorPath: CALayer {
associatedtype A: Anchor where A.P == Self
var anchors: [A] { get set }
}
// Implementation.swift
import Foundation
import UIKit
public class AnchorLayer<P: AnchorPath>: CALayer {
public unowned let path: P
public var isActive: Bool = false
public var x: Double {
get { position.x }
set { position.x = newValue }
}
public var y: Double {
get { position.y }
set { position.y = newValue }
}
public init(path: P) {
self.path = path
super.init()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
}
public class AnchorPathLayer<A: Anchor>: CALayer {
public var anchors: [A] = []
}
public final class CVAnchor: AnchorLayer<CVPath>, Anchor {
}
public final class CVPath: AnchorPathLayer<CVAnchor>, AnchorPath {
}
ProtocolModule contains the following code：
import Foundation
public protocol TableProtocol: AnyObject {
associatedtype Row: TableRowProtocol
associatedtype Column: TableColummProtocol where Column.RowContent == Self.Row.Value
var name: String? { get }
var rows: [Row] { get }
var columns: [Column] { get }
}
public protocol TableRowProtocol: AnyObject {
associatedtype Value
var name: String { get }
var data: Value { get set }
}
public protocol TableColummProtocol {
associatedtype RowContent
var name: String { get }
var keyPath: WritableKeyPath<RowContent, Double> { get }
}
public class TableRow<Value, Column: TableColummProtocol>: TableRowProtocol {
public var name: String
public var data: Column.RowContent
public init(data: Column.RowContent, name: String) {
self.data = data
self.name = name
}
}
public class TableColumn<Value>: TableColummProtocol {
public var name: String
public var keyPath: WritableKeyPath<Value, Double>
public init(name: String, keyPath: WritableKeyPath<Value, Double>) {
self.name = name
self.keyPath = keyPath
}
}
App contains the following code：
import Foundation
import DataModule
import ProtocolModule
extension CVPath: TableProtocol {
public typealias Row = TableRow<CVPath, TableColumn<CVAnchor>>
public typealias Column = TableColumn<CVAnchor>
public var rows: [Row] {
let hasSelected = self.anchors.contains{ $0.isActive }
return self.anchors.enumerated().compactMap { index, knot in
if !hasSelected || (hasSelected && knot.isActive) {
return Row(data: knot, name: "knot[\(index)]")
} else {
return nil
}
}
}
public var columns: [Column] {
return [
Column(name: "x", keyPath: \.x),
Column(name: "y", keyPath: \.y)
]
}
}
the compile error：
Command SwiftEmitModule failed with a nonzero exit code
Command SwiftCompile failed with a nonzero exit code