Ah got it, thanks for the quick reply!

Describe the bug

Using version 1.0.0-alpha.15, Xcode is not able to build for SwiftUI previews because of what is seemingly a duplicate symbols warning.

The diagnostics messages are:

Swift package target 'CNIODarwin' is linked as a static library by 'NIOTransportServices' and 2 other targets. This will result in duplication of library code.

----------------------------------------

SchemeBuildError: Failed to build the scheme "Example"

Swift package target 'CNIODarwin' is linked as a static library by 'NIOTransportServices' and 2 other targets. This will result in duplication of library code.

Build system information:
error: Swift package target 'CNIODarwin' is linked as a static library by 'NIOTransportServices' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOAtomics' is linked as a static library by 'NIOTransportServices' and 3 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'NIOConcurrencyHelpers' is linked as a static library by 'NIOTransportServices' and 3 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOSHA1' is linked as a static library by 'NIOTransportServices' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'NIO' is linked as a static library by 'NIOTransportServices' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOLinux' is linked as a static library by 'NIOTransportServices' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIODarwin' is linked as a static library by 'NIOSSL' and 'NIOTLS'. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOAtomics' is linked as a static library by 'NIOSSL' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'NIOConcurrencyHelpers' is linked as a static library by 'NIOSSL' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOSHA1' is linked as a static library by 'NIOSSL' and 'NIOTLS'. This will result in duplication of library code.


Build system information:
error: Swift package target 'NIO' is linked as a static library by 'NIOSSL' and 'NIOTLS'. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOLinux' is linked as a static library by 'NIOSSL' and 'NIOTLS'. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIODarwin' is linked as a static library by 'NIOHTTP2' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOAtomics' is linked as a static library by 'NIOHTTP2' and 3 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'NIOConcurrencyHelpers' is linked as a static library by 'NIOHTTP2' and 3 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOSHA1' is linked as a static library by 'NIOHTTP2' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'NIO' is linked as a static library by 'NIOHTTP2' and 2 other targets. This will result in duplication of library code.


Build system information:
error: Swift package target 'CNIOLinux' is linked as a static library by 'NIOHTTP2' and 2 other targets. This will result in duplication of library code.

To reproduce

Steps to reproduce the bug you've found:

1. Create a new SwiftUI project for iOS
2. Include grpc-swift as a dependency via SPM
3. Attempt to render SwiftUI preview
4. Observe failure

Expected behaviour

SwiftUI previews work as intended by Xcode

I am seeing this same issue, and getting two warnings:

Button { // No Space in Method Call Violation
    print("Button tapped")
} label: { // Multiple Closures with Trailing Closure Violation
    Text("Button")
}