dyld: Library not loaded: @rpath/lib_InternalSwiftSyntaxParser.dylib

[kean]

Environment

Xcode 11.4

Steps

• Pull the latest swift-doc from master
• Open Package.swift
• Run swift-doc target or unit tests for SwiftDoc library

Observed result

dyld: Library not loaded: @rpath/lib_InternalSwiftSyntaxParser.dylib
Referenced from: /Users/kean/Library/Developer/Xcode/DerivedData/swift-doc-enlnpuwdeszizwbdykidcjodocbk/Build/Products/Debug/swift-doc
Reason: image not found

Related

realm/SwiftLint#3105

[mattt]

Also related to SwiftDocOrg/SwiftSemantics#2

[kean]

Closing as duplicate.

[mattt]

Actually, I think there's a SwiftDoc-specific action to be taken for this. Until this is resolved in a future version of Xcode, we should at least document this as a Known Issue (similar to what we're doing in SwiftSemantics except, well... less awkwardly-written).

[kean]

@mattt, do you know if there is a workaround?

[mattt]

@kean Last I checked, you can run swift package generate-xcodeproj to generate an Xcode project and then xed <#Package#>.xcodeproj to open the generated project directly.

[kean]

It results in another issue on my machine.

[mattt]

😞 Woof. Thanks for giving that a try. Sorry that isn't a viable solution in the meantime. I'll work to get that documented as a known issue and keep an eye out for a long-term fix in Xcode.

[kean]

Is there any way I can run the executable and/or unit tests with the debugger attached in Xcode?

[mattt]

Not that I know of, unfortunately. I've been getting by with Console.app crash logs and print statements as needed, but would definitely prefer a real debugging setup.

[kean]

Apparently, the issue is that SwiftSyntax uses some private library named lib_InternalSwiftSyntaxParser.dylib. This library is not yet distributed as part of the OS (as of macOS 10.15.4). It is, however, available in Xcode 11.4:

/Applications/Xcode.app/Contents/Frameworks/lib_InternalSwiftSyntaxParser.dylib

So all you need to do is modify @​rpath to make sure that the library is there when swift-doc is executed. Unfortunately, there doesn't seem to be any way to do that using Swift Package Manager.

What you can do is change environment variables, like DYLD_LIBRARY_PATH, when running the tests. With this setting, I am now able to run SwiftDoc unit tests from Xcode with debugger attached.

Naturally, there are multiple ways to set environment variables. Another option is to add it to .bash_profile.

[JaapWijnen]

This doesn't work for me unfortunately. Any updates on how to fix this? Trying to run the swiftdoc tests on a local fork. (I'm also getting the redefinition of module libxml2)

[mattt]

@kean Thanks for sharing your workaround for this issue.

I'm happy to report that I was able to get this working in Xcode 12.5 by using the latest OSS Toolchain. I just updated the README to document this with f2e3185.