iOS build: the "-gcc_flags -dead_strip" Mtouch argument doesn't work

[rolfbjarne]

From @vasile135 on Fri, 18 Nov 2022 15:04:29 GMT

Description

Have a working Xamarin Forms application that relies on some iOS native static libraries.
Trying to migrate the solution to .NET MAUI.
When adding the same static libraries with the same configurations and the same gcc flag, the MAUI application build fails with:
Error: clang++ exited with code 1: duplicate symbol '_crypto_onetimeauth_verify' in: /Users/hetzner/Desktop/TestIndyLibraries/iOSBindingLibrary/bin/Debug/net7.0-ios/iOSBindingLibrary.resources/libsodium.a(libsodium_la-crypto_onetimeauth.o) /Users/hetzner/Desktop/TestIndyLibraries/iOSBindingLibrary/bin/Debug/net7.0-ios/iOSBindingLibrary.resources/libzmq.a(src_libzmq_la-tweetnacl.o)
In Xamarin, I believe that the error is addressed by the following Mtouch extra argument:
-gcc_flags -dead_strip -v

Steps to Reproduce

1. In order to add native references, added an iOS Binding project to the MAUI solution.

2. Added native references (one of it is C++):
   

3. Added an additional Mtouch argument to the application project:
   -gcc_flags -dead_strip -v

4. Installed the nuget package that uses these native libraries (Hyperledger.Aries).

5. When trying to build, the following error occurs:
   Error: clang++ exited with code 1: duplicate symbol '_crypto_onetimeauth_verify' in:

From here I conclude that the gcc flag was not applied.

Link to public reproduction project repository

Version with bug

7.0 (current)

Last version that worked well

Unknown/Other

Affected platforms

iOS, macOS

Affected platform versions

iOS 16

Did you find any workaround?

No

Relevant log output

No response

Copied from original issue dotnet/maui#11477

[rolfbjarne]

From @jsuarezruiz on Mon, 21 Nov 2022 15:29:54 GMT

cc @rolfbjarne

[rolfbjarne]

From @rolfbjarne on Mon, 21 Nov 2022 20:38:49 GMT

@vasile135 could you get a binary build log and attach it here?

[rolfbjarne]

From @vasile135 on Tue, 22 Nov 2022 08:41:17 GMT

@vasile135 could you get a binary build log and attach it here?

Sure.
msbuild.zip

[rolfbjarne]

@vasile135: can you try adding an equals sign after -gcc_flags like this instead:

<MtouchExtraArgs>-gcc_flags=-dead_strip -v</MtouchExtraArgs>

[vasile135]

@vasile135: can you try adding an equals sign after -gcc_flags like this instead:

<MtouchExtraArgs>-gcc_flags=-dead_strip -v</MtouchExtraArgs>

Tried, doesn't work either.

[rolfbjarne]

@vasile135: can you try adding an equals sign after -gcc_flags like this instead:

<MtouchExtraArgs>-gcc_flags=-dead_strip -v</MtouchExtraArgs>

Tried, doesn't work either.

Can you get a new binlog then?

[vasile135]

However, with the "-gcc_flags=-dead_strip -v" I already see the "-dead_strip" in the binlog file:

[vasile135]

The new binlog:
msbuild (1).zip

[vasile135]

Just to ensure that the "-dead_strip" flag affects the linking in my case, tried to remove it from the working Xamarin Forms application, and then the build fails with:
/Users/hetzner/Projects/TestIndyXamarin/TestXAmarinIndy.iOS/MTOUCH: Error MT5201: Native linking failed. Please review the build log and the user flags provided to gcc: Libraries/libcrypto.a Libraries/libindy.a Libraries/libsodium.a Libraries/libssl.a Libraries/libzmq.a (MT5201) (TestIndyXamarin.iOS)

[rolfbjarne]

@vasile135 did you upload the wrong zip file? Because that binlog is from a build that still has:

<MtouchExtraArgs>-gcc_flags -dead_strip -v</MtouchExtraArgs>