How to `Always Embed Swift Standard Libraries`?

Using Swift
1

We have CLI tool written in Swift for common usage (Android and iOS developers) on macOS. Android developers without Xcode installation get the following error:

dyld: Library not loaded: @rpath/libswiftCore.dylib
Referenced from: ~/git/myClITool/macosBin Reason: image not found
Abort trap: 6

We found that enabling Always Embed Swift Standard Libraries in Xcode would most likely help, but this CLI tool is exported with SPM, ignoring all Xcode settings.

How can I achieve this build behaviour using SPM only?

2

If your developers are using at least macOS 10.14.4, those binaries should be linked against the libswiftCore.dylib in the OS, which doesn't need Xcode. What version of macOS are they using?

1 Like
3

10.14.4 was the first version to have the Swift libraries built into the OS. For older macOS versions, they will need to install the Swift 5 Runtime Support package:

https://support.apple.com/kb/DL1998?locale=en_US

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4

I ran into a similar problem recently when I rebuilt protoc-gen-swift with the Xcode 11.1 toolchain. (That is the Protocol Buffers compiler plugin to generate Swift bindings.)

Previously I built it with Xcode 9.3 on macOS 10.13 using the command swift build -c release -Xswiftc -static-stdlib. This gave me an executable that I could copy around and run from any directory on any host.

When I rebuilt it using the Xcode 11.1 toolchain with the same command, I could no longer run it:

:; .build/x86_64-apple-macosx/release/protoc-gen-swift
dyld: Library not loaded: @rpath/libswiftCore.dylib
  Referenced from: /Users/rmayoff/P/clarity/protobuf/src/swift-protobuf-1.7.0/.build/x86_64-apple-macosx/release/protoc-gen-swift
  Reason: image not found
Abort trap: 6

I had to remove the -Xswiftc -static-stdlib flags to get a working executable.

1 Like
5

-static-stdlib is no longer supported, yeah.

6

They have various versions of macOS (10.14.0 and above).
Should I add a package dependency to "libswiftCore.dylib"? Is that even possible?

7

My goal is to create a single executable that I can distribute to the team, without additional installation requirements. If "-static-stdlib" is no longer supported, maybe should I add an explicit macOS version requirement? Or is there a better way to achieve the goal?

8

You'll either need to require macOS 10.14.4 or later, or ask your clients to install the Swift Runtime Libraries package on their older macOS versions.

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