net: macOS link of Go c-archive now requires -lresolv in 1.20 #58159

bradfitz · 2023-01-31T06:47:58Z

Go 1.20rc3.

I tried to convert our application (@tailscale) over to Go 1.20 but hit macOS compilation errors in Xcode for our target (a network extension) that links in Go code:

    /Applications/Xcode-13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang -target arm64-apple-macos10.13 -isysroot /Applications/Xcode-13.4.1.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX12.3.sdk -L/Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/BuildProductsPath/Release -F/Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/BuildProductsPath/Release -filelist /Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/IntermediateBuildFilesPath/IPN.build/Release/IPNExtension-macOS.build/Objects-normal/arm64/IPNExtension.LinkFileList -exported_symbols_list IPNExtension/exported-symbols.exp -Xlinker -rpath -Xlinker /usr/lib/swift -Xlinker -rpath -Xlinker @executable_path/../Frameworks -Xlinker -rpath -Xlinker @executable_path/../../../../Frameworks -dead_strip -Xlinker -object_path_lto -Xlinker /Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/IntermediateBuildFilesPath/IPN.build/Release/IPNExtension-macOS.build/Objects-normal/arm64/IPNExtension_lto.o -fapplication-extension -fobjc-link-runtime -L/Applications/Xcode-13.4.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx -L/usr/lib/swift -Xlinker -add_ast_path -Xlinker /Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/IntermediateBuildFilesPath/IPN.build/Release/IPNExtension-macOS.build/Objects-normal/arm64/IPNExtension.swiftmodule -e _NSExtensionMain -lipn-go-arm64\ x86_64 -framework NetworkExtension -Xlinker -dependency_info -Xlinker /Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/IntermediateBuildFilesPath/IPN.build/Release/IPNExtension-macOS.build/Objects-normal/arm64/IPNExtension_dependency_info.dat -o /Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/IntermediateBuildFilesPath/IPN.build/Release/IPNExtension-macOS.build/Objects-normal/arm64/Binary/IPNExtension
Undefined symbols for architecture arm64:
  "_res_9_nsearch", referenced from:
      _internal/syscall/unix.libresolv_res_9_nsearch_trampoline.abi0 in libipn-go-arm64 x86_64.a(go.o)
  "_res_9_nclose", referenced from:
      _internal/syscall/unix.libresolv_res_9_nclose_trampoline.abi0 in libipn-go-arm64 x86_64.a(go.o)
  "_res_9_ninit", referenced from:
      _internal/syscall/unix.libresolv_res_9_ninit_trampoline.abi0 in libipn-go-arm64 x86_64.a(go.o)
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

...

The following build commands failed:
	Ld /Users/github-ci/Library/Developer/Xcode/DerivedData/IPN-dcmqhkiofztpxzcjkertpymoivvw/Build/Intermediates.noindex/ArchiveIntermediates/IPN-macOS/IntermediateBuildFilesPath/IPN.build/Release/IPNExtension-macOS.build/Objects-normal/arm64/Binary/IPNExtension normal arm64 (in target 'IPNExtension-macOS' from project 'IPN')

I assume this is fallout from https://tip.golang.org/doc/go1.20#cgo ...

On macOS, the net and os/user packages have been rewritten not to use cgo: the same code is now used for cgo and non-cgo builds as well as cross-compiled builds.

Unfortunately I don't have a small easy repro. (Nothing is small or easy with Xcode)

/cc @rsc @ianlancetaylor

The text was updated successfully, but these errors were encountered:

ianlancetaylor · 2023-01-31T15:04:41Z

Can you outline the overall build here? For example, is this using -buildmode=c-archive and linking that into a C program? Are you passing -lresolv when linking the C program?

mknyszek · 2023-01-31T15:57:37Z

CC @neild

bcmills · 2023-01-31T16:28:28Z

The reference to res_9_nclose was added in CL 446179 for #50101.

bradfitz · 2023-01-31T16:54:53Z

Yeah, this is using -buildmode=c-archive, ultimately linked into a Swift program (but Swift thinks the Go is C). I'll try to trace through the build mess to see where/whether -lresolv is set.

ianlancetaylor · 2023-01-31T17:04:17Z

When linking a Go program, -lresolv is added by the line //go:cgo_ldflag "-lresolv" in internal/syscall/unix/net_darwin.go. In the past a Go c-archive built without cgo support would not require it. However, in Go 1.20, it is now required. But as far as I can recall we don't have a way for a Go c-archive to communicate which libraries it depends on to the C program.

If adding -lresolv to your command line fixes the problem, this should likely be added to the release notes and the net package documentation.

bradfitz · 2023-01-31T17:06:56Z

Thanks! Adding -lresolv seemed to fix it. It at least is getting further now. Still waiting for the build to finish.

Edit: yup, that did it.

xDragonZ · 2023-02-08T02:35:04Z

After compile for ios using macos throwing this error too Undefined symbol: _res_9_nclose

Any idea where to add the -lresolv for gomobile?

flag provided but not defined: -lresolv

gomobile: iossimulator/amd64: go build -v -ldflags -s -w -lresolv -buildmode=c-archive -o test-iossimulator-amd64.a ./gobind failed: exit status 1

bcmills · 2023-02-08T15:18:26Z

@xDragonZ, I would suggest filing a separate issue for the x/mobile maintainers to follow up on, with exact steps to reproduce the error.

(The -lresolv flag needs to be passed to the C linker, however that happens in gomobile.)

ghost · 2023-02-09T13:08:29Z

same issue for me

CGO_ENABLED=1 \
GOOS=ios \
GOARCH=arm64 \
SDK=iphoneos \
CC=$(shell go env GOROOT)/misc/ios/clangwrap.sh \
CGO_CFLAGS="-fembed-bitcode" \
go build -trimpath -ldflags="-w -s" -lresolv -buildmode=c-archive

resut:

flag provided but not defined: -lresolv
usage: go build [-o output] [build flags] [packages]
Run 'go help build' for details.
make: *** [ios-arm64] Error 2

i need help !

bradfitz · 2023-02-09T13:17:39Z

Try -ldflags="-w -s -lresolv" with it in the quoted ldflags part.

ghost · 2023-02-09T13:24:45Z

-ldflags="-w -s -lresolv"在引用的 ldflags 部分尝试使用它。

CGO_ENABLED=1 \
GOOS=ios \
GOARCH=arm64 \
SDK=iphoneos \
CC=$(shell go env GOROOT)/misc/ios/clangwrap.sh \
CGO_CFLAGS="-fembed-bitcode" \
go build -trimpath -ldflags="-w -s -lresolv"  -buildmode=c-archive

no luck,it give me
flag provided but not defined: -lresolv

ghost · 2023-02-09T13:31:46Z

btw,add CGO_LDFLAG="-lresolv" in cmd line can not fix it

bradfitz · 2023-02-09T13:42:38Z

Oh, extldflags. Something like go build -trimpath -buildmode=c-archive -ldflags '-w -s -extldflags "-lresolve"' IIRC but I didn't test that either.

ghost · 2023-02-09T14:08:11Z

Oh, extldflags. Something like go build -trimpath -buildmode=c-archive -ldflags '-w -s -extldflags "-lresolve"' IIRC but I didn't test that either.

go build -trimpath -buildmode=c-archive -ldflags '-w -s "-extldflags=-lresolv" ' build success,but still got res_9_nsearch error

bcmills · 2023-02-09T14:14:41Z

still got res_9_nsearch error

What was the exact error message?

ghost · 2023-02-10T03:10:31Z

仍然有 res_9_nsearch 错误

确切的错误信息是什么？

xcode build show errors

jsoneaday · 2023-02-23T23:03:41Z

When I run the given command go build -trimpath -buildmode=c-archive -ldflags '-w -s -extldflags "-lresolve"' ./src/golang it completes without error and gives me a golang.a file.
However I'm trying to do something a bit diff in that I want to get a C binary to use in Nodejs. So I tried calling go build -trimpath -buildmode=c-shared -ldflags '-w -s -extldflags "-lresolve"' ./src/golang

It gives me error

# archwayhq/keyring-go/src/golang
/usr/local/go/pkg/tool/darwin_amd64/link: running clang failed: exit status 1
ld: library not found for -lresolve
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I am on a M1 Mac so I tried changing GOARCH to arm64, but that gives me this error package archwayhq/keyring-go/src/golang: build constraints exclude all Go files in /Users/davidchoi/Work/philabs/keyring/keyring-go/src/golang

ianlancetaylor · 2023-02-23T23:09:41Z

It's -lresolv, not -lresolve.

jsoneaday · 2023-02-23T23:10:43Z

I just copied and pasted what was there

ianlancetaylor · 2023-02-23T23:12:04Z

What you cut and pasted shows you using -lresolve, and getting an error saying library not found for -lresolve. I'm telling you that instead of using -lresolve you should use -lresolv. You are adding an "e" that shouldn't be there.

jsoneaday · 2023-02-23T23:13:38Z

Yeah I got it. Relax.

Not sure why lserve worked for c-archive, but removing e is working for c-shared. But now only getting the one binary, I called it keyring.so, but no h header file.

gopherbot · 2023-02-23T23:14:08Z

Change https://go.dev/cl/470917 mentions this issue: net: document that on macOS c-archive requires -lresolv

jsoneaday · 2023-02-23T23:17:15Z

Yes thank you. But I'm doing a c-shared, not c-archive. It did build but I see no h header file. If I understand correctly I need a .cc file that imports the C header and exposes the stuff to Nodejs.

Is this something new in 1.20.1 where a h header is not needed or something?

ianlancetaylor · 2023-02-23T23:22:39Z

Nothing should have changed in 1.20 as far as generating a header file for c-shared goes. That sounds like a different problem that should be discussed in a different issue. Thanks.

gopherbot · 2023-02-23T23:23:57Z

Change https://go.dev/cl/470856 mentions this issue: doc/go1.20: mention -lresolv requirement for c-archive on macOS

For #58159 Change-Id: Iff8e017c568be111c494992cb6fe62d469e0f981 Reviewed-on: https://go-review.googlesource.com/c/go/+/470917 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Bryan Mills <bcmills@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Than McIntosh <thanm@google.com> TryBot-Result: Gopher Robot <gobot@golang.org>

For golang/go#58159 Change-Id: I4099bba337acdb82e61cddcf099aa4c1c464d387 Reviewed-on: https://go-review.googlesource.com/c/website/+/470856 Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Run-TryBot: Ian Lance Taylor <iant@google.com> Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Auto-Submit: Ian Lance Taylor <iant@google.com>

ianlancetaylor · 2023-03-02T21:53:11Z

This is now documented.

Reference bug: golang/go#58159

bradfitz mentioned this issue Jan 31, 2023

Upgrade to Go 1.20 tailscale/tailscale#7123

Closed

mknyszek added the NeedsInvestigation Someone must examine and confirm this is a valid issue and not a duplicate of an existing one. label Jan 31, 2023

mknyszek added this to the Go1.21 milestone Jan 31, 2023

bcmills added the OS-Darwin label Jan 31, 2023

bcmills added the WaitingForInfo Issue is not actionable because of missing required information, which needs to be provided. label Jan 31, 2023

bradfitz changed the title ~~net: macOS compilation errors with Go 1.20rc3 (Undefined symbols ... _res_9_nsearch, etc)~~ net: macOS link of Go c-archive now requires -lresolve in 1.20 Jan 31, 2023

bradfitz added the Documentation label Jan 31, 2023

bradfitz changed the title ~~net: macOS link of Go c-archive now requires -lresolve in 1.20~~ net: macOS link of Go c-archive now requires -lresolv in 1.20 Jan 31, 2023

xDragonZ mentioned this issue Feb 8, 2023

x/mobile: Undefined symbols _res_9_nclose with Go 1.20 #58416

Open

bcmills added WaitingForInfo Issue is not actionable because of missing required information, which needs to be provided. and removed WaitingForInfo Issue is not actionable because of missing required information, which needs to be provided. labels Feb 9, 2023

ianlancetaylor closed this as completed Mar 2, 2023

pdecat mentioned this issue Mar 21, 2023

Use go version 1.20 to build and test FDW turbot/steampipe-postgres-fdw#296

Open

joshuataylor mentioned this issue May 1, 2023

Static builds on MacOS ARM64 (Apple Silicon aka M1/M2) don't seem to work as expected zyedidia/micro#2812

Open

Bluebugs pushed a commit to fyne-io/fyne-cross that referenced this issue May 5, 2023

Go now require to add -lresolv when compiling for darwin with go1.20.

2d58a25

Reference bug: golang/go#58159

Bluebugs mentioned this issue May 6, 2023

Bugs/support go1.20 darwin fyne-io/fyne-cross#194

Open

binaek mentioned this issue Aug 18, 2023

Upgrade go version turbot/steampipe-postgres-fdw#339

Closed

Techassi mentioned this issue Oct 4, 2023

Build binaries for stackablectl stackabletech/stackable-cockpit#92

Open

golang locked and limited conversation to collaborators Mar 1, 2024

gopherbot added the FrozenDueToAge label Mar 1, 2024

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

net: macOS link of Go c-archive now requires -lresolv in 1.20 #58159

net: macOS link of Go c-archive now requires -lresolv in 1.20 #58159

bradfitz commented Jan 31, 2023

ianlancetaylor commented Jan 31, 2023

mknyszek commented Jan 31, 2023

bcmills commented Jan 31, 2023

bradfitz commented Jan 31, 2023

ianlancetaylor commented Jan 31, 2023

bradfitz commented Jan 31, 2023 •

edited

xDragonZ commented Feb 8, 2023

bcmills commented Feb 8, 2023

ghost commented Feb 9, 2023

bradfitz commented Feb 9, 2023

ghost commented Feb 9, 2023

ghost commented Feb 9, 2023

bradfitz commented Feb 9, 2023

ghost commented Feb 9, 2023

bcmills commented Feb 9, 2023

ghost commented Feb 10, 2023 •

edited by ghost

jsoneaday commented Feb 23, 2023

ianlancetaylor commented Feb 23, 2023

jsoneaday commented Feb 23, 2023

ianlancetaylor commented Feb 23, 2023

jsoneaday commented Feb 23, 2023

gopherbot commented Feb 23, 2023

jsoneaday commented Feb 23, 2023

ianlancetaylor commented Feb 23, 2023

gopherbot commented Feb 23, 2023

ianlancetaylor commented Mar 2, 2023

net: macOS link of Go c-archive now requires -lresolv in 1.20 #58159

net: macOS link of Go c-archive now requires -lresolv in 1.20 #58159

Comments

bradfitz commented Jan 31, 2023

ianlancetaylor commented Jan 31, 2023

mknyszek commented Jan 31, 2023

bcmills commented Jan 31, 2023

bradfitz commented Jan 31, 2023

ianlancetaylor commented Jan 31, 2023

bradfitz commented Jan 31, 2023 • edited

xDragonZ commented Feb 8, 2023

bcmills commented Feb 8, 2023

ghost commented Feb 9, 2023

bradfitz commented Feb 9, 2023

ghost commented Feb 9, 2023

ghost commented Feb 9, 2023

bradfitz commented Feb 9, 2023

ghost commented Feb 9, 2023

bcmills commented Feb 9, 2023

ghost commented Feb 10, 2023 • edited by ghost

jsoneaday commented Feb 23, 2023

ianlancetaylor commented Feb 23, 2023

jsoneaday commented Feb 23, 2023

ianlancetaylor commented Feb 23, 2023

jsoneaday commented Feb 23, 2023

gopherbot commented Feb 23, 2023

jsoneaday commented Feb 23, 2023

ianlancetaylor commented Feb 23, 2023

gopherbot commented Feb 23, 2023

ianlancetaylor commented Mar 2, 2023

bradfitz commented Jan 31, 2023 •

edited

ghost commented Feb 10, 2023 •

edited by ghost