Android build fails with Abseil/GRPC undefined symbols from Convai 5.4 plugin

gtree · October 27, 2025, 7:43am

Hi all — I’m trying to package Android (ASTC, Shipping, arm64) in UE 5.4 with the Convai 5.4 plugin enabled. The linker fails with Abseil/gRPC undefined symbols:

ld.lld: error: undefined symbol: absl::lts_2020_09_23::string_view::rfind(…)
ld.lld: error: undefined symbol: absl::lts_2020_09_23::Mutex::Lock()
ld.lld: error: undefined symbol: absl::lts_2020_09_23::CondVar::Wait(…)
ld.lld: error: undefined symbol: Convai_AbslInternalSpinLockWake

Environment:

UE 5.4 (Windows)
Android NDK r25c, API 33
Build works if I disable Convai; fails when enabled

It looks like the plugin’s gRPC libs need matching Abseil libs (possibly with a custom prefix).
Could someone please share the correct Android static libs and link order (or the exact versions/flags to rebuild), or a quick workaround to disable Convai only on Android?

Happy to provide logs and my Build.cs.
Thanks!

gtree · October 29, 2025, 12:24pm

Hello. Please someone help me. Thanks

K3 · October 29, 2025, 1:49pm

Could you please share the logs?

gtree · October 29, 2025, 1:59pm

UATHelper: Packaging (Android (ASTC)): ********** BUILD COMMAND STARTED **********
UATHelper: Packaging (Android (ASTC)): Running: C:\Program Files\Epic Games\UE_5.4\Engine\Binaries\ThirdParty\DotNet\6.0.302\windows\dotnet.exe "C:\Program Files\Epic Games\UE_5.4\Engine\Binaries\DotNET\UnrealBuildTool\UnrealBuildTool.dll" leeds_rhinos Android Shipping -Project="F:\Unreal Projects\leeds_rhinos\leeds_rhinos.uproject" -Manifest="F:\Unreal Projects\leeds_rhinos\Intermediate\Build\Manifest.xml"  -remoteini="F:\Unreal Projects\leeds_rhinos"  -skipdeploy -distribution  -log="C:\Users\jonat\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_5.4\UBA-leeds_
rhinos-Android-Shipping.txt"
UATHelper: Packaging (Android (ASTC)): Log file: C:\Users\jonat\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_5.4\UBA-leeds_rhinos-Android-Shipping.txt
UATHelper: Packaging (Android (ASTC)): Creating makefile for leeds_rhinos (command line arguments changed)
UATHelper: Packaging (Android (ASTC)): Android (8490178, based on r450784d) clang version 14.0.6 (https://android.googlesource.com/toolchain/llvm-project 4c603efb0cca074e9238af8b4106c30add4418f6)
UATHelper: Packaging (Android (ASTC)): Target: x86_64-w64-windows-gnu
UATHelper: Packaging (Android (ASTC)): Thread model: posix
UATHelper: Packaging (Android (ASTC)): InstalledDir: C:/Users/jonat/AppData/Local/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/bin
UATHelper: Packaging (Android (ASTC)): Compiling with ray tracing enabled
UATHelper: Packaging (Android (ASTC)): Android (8490178, based on r450784d) clang version 14.0.6 (https://android.googlesource.com/toolchain/llvm-project 4c603efb0cca074e9238af8b4106c30add4418f6)
UATHelper: Packaging (Android (ASTC)): Target: x86_64-w64-windows-gnu
UATHelper: Packaging (Android (ASTC)): Thread model: posix
UATHelper: Packaging (Android (ASTC)): InstalledDir: C:/Users/jonat/AppData/Local/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/bin
UATHelper: Packaging (Android (ASTC)): NDK toolchain: r25b, NDK version: 250200, ClangVersion: 14.0.6
UATHelper: Packaging (Android (ASTC)): Compiling Native 64-bit code with NDK API 'android-26'
UATHelper: Packaging (Android (ASTC)): Link: C:\Users\jonat\AppData\Local\Android\Sdk\ndk\25.1.8937393\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe  -static-libstdc++ -no-canonical-prefixes -shared -Wl,-Bsymbolic -Wl,--no-undefined -Wl,--gc-sections --target=aarch64-none-linux-android26 --gcc-toolchain="C:/Users/jonat/AppData/Local/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64" --sysroot="C:/Users/jonat/AppData/Local/Android/Sdk/ndk/25.1.8937393/toolchains/llvm/prebuilt/windows-x86_64/sysroot" -DANDROID=1 -march=armv8-a -Wl,--icf=all -Wl,-O3 -Wl,-no-pie -fuse-
ld=lld -Wl,-soname,libUnreal.so -Wl,--version-script="F:/Unreal Projects/leeds_rhinos/Intermediate/Build/Android/a/leeds_rhinos/Shipping/ExportSymbols.ldscript" -Wl,--build-id=sha1 -Wl,--pack-dyn-relocs=android+relr,--use-android-relr-tags -Wl,--hash-style=gnu -z max-page-size=65536 -o "F:/Unreal Projects/leeds_rhinos/Binaries/Android/leeds_rhinos-Android-Shipping-arm64.so" @"F:/Unreal Projects/leeds_rhinos/Intermediate/Build/Android/a/leeds_rhinos/Shipping/leeds_rhinos-Android-Shipping-arm64.so.rsp"
UATHelper: Packaging (Android (ASTC)): Writing manifest to F:\Unreal Projects\leeds_rhinos\Intermediate\Build\Manifest.xml
UATHelper: Packaging (Android (ASTC)): Building leeds_rhinos...
UATHelper: Packaging (Android (ASTC)): [Upgrade]
UATHelper: Packaging (Android (ASTC)): [Upgrade] Using backward-compatible include order. The latest version of UE has changed the order of includes, which may require code changes. The current setting is:
UATHelper: Packaging (Android (ASTC)): [Upgrade]     IncludeOrderVersion = EngineIncludeOrderVersion.Oldest
UATHelper: Packaging (Android (ASTC)): [Upgrade] Suppress this message by setting 'IncludeOrderVersion = EngineIncludeOrderVersion.Latest;' in leeds_rhinos.Target.cs.
UATHelper: Packaging (Android (ASTC)): [Upgrade] Alternatively you can set this to 'EngineIncludeOrderVersion.Latest' to always use the latest include order. This will potentially cause compile errors when integrating new versions of the engine.
UATHelper: Packaging (Android (ASTC)): [Upgrade]
UATHelper: Packaging (Android (ASTC)): [Adaptive Build] Excluded from VivoxCore unity file: AccountId.cpp, AudioDeviceImpl.cpp, AudioDevicesImpl.cpp, Channel3DProperties.cpp, ChannelConnectionState.cpp, ChannelId.cpp, ChannelSession.cpp, ChannelTextMessage.cpp, ClientImpl.cpp, ConnectionState.cpp, DirectedTextMessage.cpp, IAudioDevice.cpp, IAudioDevices.cpp, IChannelConnectionState.cpp, IChannelSession.cpp, IChannelTextMessage.cpp, IClient.cpp, IDirectedTextMessage.cpp, ILoginSession.cpp, IParticipant.cpp, IParticipantProperties.cpp, IPresenceLocation.cpp, IPresenceSubscription.cpp, ITextMessa
ge.cpp, ITextToSpeech.cpp, ITranscribedMessage.cpp, ITTSAudioBuffer.cpp, ITTSMessage.cpp, ITTSVoice.cpp, LoginSession.cpp, Participant.cpp, Presence.cpp, PresenceLocation.cpp, PresenceSubscription.cpp, TextToSpeech.cpp, TranscribedMessage.cpp, TTSAudioBufferImpl.cpp, TTSMessageImpl.cpp, TTSVoiceImpl.cpp, VivoxConfig.cpp, VivoxCore.cpp, VivoxNativeSdk.cpp
UATHelper: Packaging (Android (ASTC)): [Adaptive Build] Excluded from VivoxModeration unity file: OpenAPIBaseModel.cpp, OpenAPIErrorsErrorResponseBody.cpp, OpenAPIHelpers.cpp, OpenAPIModelPlayersRequest.cpp, OpenAPIModelPostReportRequest.cpp, OpenAPIModelVivoxChannelRequest.cpp, OpenAPIReportApi.cpp, OpenAPIReportApiOperations.cpp, VivoxModerationApi.cpp, VivoxModerationModule.cpp, VivoxModerationSubsystem.cpp, WrappedModerationApi.cpp
UATHelper: Packaging (Android (ASTC)): [Adaptive Build] Excluded from AndroidVulkanVideoFactory unity file: AndroidVulkanVideoFactoryModule.cpp
UATHelper: Packaging (Android (ASTC)): Determining max actions to execute in parallel (10 physical cores, 20 logical cores)
UATHelper: Packaging (Android (ASTC)):   Executing up to 10 processes, one per physical core
UATHelper: Packaging (Android (ASTC)): Using Parallel executor to run 2 action(s)
UATHelper: Packaging (Android (ASTC)): ------ Building 2 action(s) started ------
UATHelper: Packaging (Android (ASTC)): [1/2] clang++ leeds_rhinos-Android-Shipping-arm64.so
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::string_view::rfind(char, unsigned long) const
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:31 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:31)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::JoinHostPort(absl::lts_2020_09_23::string_view, int)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: bool absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Dispatch<absl::lts_2020_09_23::string_view>(absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Data, absl::lts_2020_09_23::str_format_internal::FormatConversionSpecImpl, void*)
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:0 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:0)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::JoinHostPort(absl::lts_2020_09_23::string_view, int)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:0 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:0)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::JoinHostPort(absl::lts_2020_09_23::string_view, int)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by arg.h:405 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/internal/str_format/arg.h:405)
UATHelper: Packaging (Android (ASTC)): >>>               resolver_registry.cc.o:(grpc_core::(anonymous namespace)::RegistryState::FindResolverFactory(absl::lts_2020_09_23::string_view, grpc_core::URI*, std::__ndk1::basic_string<char, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char> >*) const) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced 9 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: bool absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Dispatch<int>(absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Data, absl::lts_2020_09_23::str_format_internal::FormatConversionSpecImpl, void*)
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:0 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:0)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::JoinHostPort(absl::lts_2020_09_23::string_view, int)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:0 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:0)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::JoinHostPort(absl::lts_2020_09_23::string_view, int)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by arg.h:405 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/internal/str_format/arg.h:405)
UATHelper: Packaging (Android (ASTC)): >>>               parsing.cc.o:(grpc_chttp2_perform_read(Convai_grpc_chttp2_transport*, grpc_slice const&)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced 21 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::str_format_internal::FormatPack(absl::lts_2020_09_23::str_format_internal::UntypedFormatSpecImpl, absl::lts_2020_09_23::Span<absl::lts_2020_09_23::str_format_internal::FormatArgImpl const>)
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:0 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:0)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::JoinHostPort(absl::lts_2020_09_23::string_view, int)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by str_format.h:340 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/str_format.h:340)
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::string_view::rfind(char, unsigned long) const
PackagingResults: Error: undefined symbol: bool absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Dispatch<absl::lts_2020_09_23::string_view>(absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Data, absl::lts_2020_09_23::str_format_internal::FormatConversionSpecImpl, void*)
PackagingResults: Error: undefined symbol: bool absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Dispatch<int>(absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Data, absl::lts_2020_09_23::str_format_internal::FormatConversionSpecImpl, void*)
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::str_format_internal::FormatPack(absl::lts_2020_09_23::str_format_internal::UntypedFormatSpecImpl, absl::lts_2020_09_23::Span<absl::lts_2020_09_23::str_format_internal::FormatArgImpl const>)
UATHelper: Packaging (Android (ASTC)): >>>               global_config_env.cc.o:(grpc_core::GlobalConfigEnvBool::Get()) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by str_format.h:340 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/str_format.h:340)
UATHelper: Packaging (Android (ASTC)): >>>               global_config_env.cc.o:(grpc_core::GlobalConfigEnvInt32::Get()) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced 129 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::string_view::find(char, unsigned long) const
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:45 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:45)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::(anonymous namespace)::DoSplitHostPort(absl::lts_2020_09_23::string_view, absl::lts_2020_09_23::string_view*, absl::lts_2020_09_23::string_view*, bool*)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:69 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:69)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::(anonymous namespace)::DoSplitHostPort(absl::lts_2020_09_23::string_view, absl::lts_2020_09_23::string_view*, absl::lts_2020_09_23::string_view*, bool*)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:71 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:71)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::(anonymous namespace)::DoSplitHostPort(absl::lts_2020_09_23::string_view, absl::lts_2020_09_23::string_view*, absl::lts_2020_09_23::string_view*, bool*)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced 7 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::base_internal::ThrowStdOutOfRange(char const*)
UATHelper: Packaging (Android (ASTC)): >>> referenced by host_port.cc:0 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gprpp/host_port.cc:0)
UATHelper: Packaging (Android (ASTC)): >>>               host_port.cc.o:(grpc_core::(anonymous namespace)::DoSplitHostPort(absl::lts_2020_09_23::string_view, absl::lts_2020_09_23::string_view*, absl::lts_2020_09_23::string_view*, bool*)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by str_split_internal.h:0 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/internal/str_split_internal.h:0)
UATHelper: Packaging (Android (ASTC)): >>>               aws_request_signer.cc.o:(absl::lts_2020_09_23::strings_internal::Splitter<absl::lts_2020_09_23::strings_internal::MaxSplitsImpl<absl::lts_2020_09_23::ByChar>, absl::lts_2020_09_23::AllowEmpty>::operator std::__ndk1::pair<absl::lts_2020_09_23::string_view, absl::lts_2020_09_23::string_view><absl::lts_2020_09_23::string_view, absl::lts_2020_09_23::string_view>() const) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by string_view.h:393 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/string_view.h:393)
UATHelper: Packaging (Android (ASTC)): >>>               external_account_credentials.cc.o:(absl::lts_2020_09_23::strings_internal::Splitter<absl::lts_2020_09_23::ByChar, absl::lts_2020_09_23::AllowEmpty>::ConvertToContainer<std::__ndk1::vector<absl::lts_2020_09_23::string_view, std::__ndk1::allocator<absl::lts_2020_09_23::string_view> >, absl::lts_2020_09_23::string_view, false>::operator()(absl::lts_2020_09_23::strings_internal::Splitter<absl::lts_2020_09_23::ByChar, absl::lts_2020_09_23::AllowEmpty> const&) const) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Conv
ai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::string_view::find(char, unsigned long) const
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::base_internal::ThrowStdOutOfRange(char const*)
UATHelper: Packaging (Android (ASTC)): >>> referenced 9 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::StrCat(absl::lts_2020_09_23::AlphaNum const&, absl::lts_2020_09_23::AlphaNum const&, absl::lts_2020_09_23::AlphaNum const&)
UATHelper: Packaging (Android (ASTC)): >>> referenced by string.cc:76 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/string.cc:76)
UATHelper: Packaging (Android (ASTC)): >>>               string.cc.o:(gpr_format_timespec(gpr_timespec)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by child_policy_handler.cc:281 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.cc:281)
UATHelper: Packaging (Android (ASTC)): >>>               child_policy_handler.cc.o:(grpc_core::ChildPolicyHandler::CreateChildPolicy(char const*, grpc_channel_args const&)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by resolver_result_parsing.cc:314 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/ext/filters/client_channel/resolver_result_parsing.cc:314)
UATHelper: Packaging (Android (ASTC)): >>>               resolver_result_parsing.cc.o:(grpc_core::internal::ClientChannelServiceConfigParser::ParseGlobalParams(grpc_channel_args const*, grpc_core::Json const&, grpc_error**)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced 50 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: bool absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Dispatch<char const*>(absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Data, absl::lts_2020_09_23::str_format_internal::FormatConversionSpecImpl, void*)
UATHelper: Packaging (Android (ASTC)): >>> referenced by arg.h:405 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/internal/str_format/arg.h:405)
UATHelper: Packaging (Android (ASTC)): >>>               global_config_env.cc.o:(grpc_core::GlobalConfigEnvBool::Get()) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by arg.h:405 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/internal/str_format/arg.h:405)
UATHelper: Packaging (Android (ASTC)): >>>               global_config_env.cc.o:(grpc_core::GlobalConfigEnvBool::Get()) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by arg.h:405 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/strings/internal/str_format/arg.h:405)
UATHelper: Packaging (Android (ASTC)): >>>               global_config_env.cc.o:(grpc_core::GlobalConfigEnvInt32::Get()) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): >>> referenced 57 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::Mutex::~Mutex()
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:50 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:50)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_mu_destroy) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::Mutex::Lock()
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:55 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:55)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_mu_lock) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::Mutex::Unlock()
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:60 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:60)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_mu_unlock) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::CondVar::~CondVar()
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::StrCat(absl::lts_2020_09_23::AlphaNum const&, absl::lts_2020_09_23::AlphaNum const&, absl::lts_2020_09_23::AlphaNum const&)
PackagingResults: Error: undefined symbol: bool absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Dispatch<char const*>(absl::lts_2020_09_23::str_format_internal::FormatArgImpl::Data, absl::lts_2020_09_23::str_format_internal::FormatConversionSpecImpl, void*)
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::Mutex::~Mutex()
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::Mutex::Lock()
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::Mutex::Unlock()
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::CondVar::~CondVar()
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:78 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:78)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_cv_destroy) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::TimeFromTimespec(timespec)
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:94 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:94)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_cv_wait) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::CondVar::WaitWithDeadline(absl::lts_2020_09_23::Mutex*, absl::lts_2020_09_23::Time)
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:92 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:92)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_cv_wait) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::CondVar::Wait(absl::lts_2020_09_23::Mutex*)
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:85 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:85)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_cv_wait) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::CondVar::Signal()
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:100 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:100)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_cv_signal) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::CondVar::SignalAll()
UATHelper: Packaging (Android (ASTC)): >>> referenced by sync_abseil.cc:105 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/lib/gpr/sync_abseil.cc:105)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(gpr_cv_broadcast) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::base_internal::SpinLockWait(std::__ndk1::atomic<unsigned int>*, int, absl::lts_2020_09_23::base_internal::SpinLockWaitTransition const*, absl::lts_2020_09_23::base_internal::SchedulingMode)
UATHelper: Packaging (Android (ASTC)): >>> referenced by call_once.h:176 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/base/call_once.h:176)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(void absl::lts_2020_09_23::base_internal::CallOnceImpl<void (*&)()>(std::__ndk1::atomic<unsigned int>*, absl::lts_2020_09_23::base_internal::SchedulingMode, void (*&)())) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: Convai_AbslInternalSpinLockWake
UATHelper: Packaging (Android (ASTC)): >>> referenced by spinlock_wait.h:84 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/third_party/abseil-cpp\absl/base/internal/spinlock_wait.h:84)
UATHelper: Packaging (Android (ASTC)): >>>               sync_abseil.cc.o:(void absl::lts_2020_09_23::base_internal::CallOnceImpl<void (*&)()>(std::__ndk1::atomic<unsigned int>*, absl::lts_2020_09_23::base_internal::SchedulingMode, void (*&)())) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgpr.a
UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: absl::lts_2020_09_23::StrCat(absl::lts_2020_09_23::AlphaNum const&, absl::lts_2020_09_23::AlphaNum const&)
UATHelper: Packaging (Android (ASTC)): >>> referenced by client_channel.cc:1940 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/ext/filters/client_channel/client_channel.cc:1940)
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::TimeFromTimespec(timespec)
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::CondVar::WaitWithDeadline(absl::lts_2020_09_23::Mutex*, absl::lts_2020_09_23::Time)
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::CondVar::Wait(absl::lts_2020_09_23::Mutex*)
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::CondVar::Signal()
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::CondVar::SignalAll()
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::base_internal::SpinLockWait(std::__ndk1::atomic<unsigned int>*, int, absl::lts_2020_09_23::base_internal::SpinLockWaitTransition const*, absl::lts_2020_09_23::base_internal::SchedulingMode)
PackagingResults: Error: undefined symbol: Convai_AbslInternalSpinLockWake
PackagingResults: Error: undefined symbol: absl::lts_2020_09_23::StrCat(absl::lts_2020_09_23::AlphaNum const&, absl::lts_2020_09_23::AlphaNum const&)
UATHelper: Packaging (Android (ASTC)): >>>               client_channel.cc.o:(grpc_core::(anonymous namespace)::ChannelData::Init(grpc_channel_element*, grpc_channel_element_args*)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by client_channel.cc:2118 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/ext/filters/client_channel/client_channel.cc:2118)
UATHelper: Packaging (Android (ASTC)): >>>               client_channel.cc.o:(grpc_core::(anonymous namespace)::ChannelData::ResolverResultHandler::ReturnResult(grpc_core::Resolver::Result)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced by lb_policy_registry.cc:157 (C:/Storage/Software/Tools/gRPC/Convai_grpc/grpc/src/core/ext/filters/client_channel/lb_policy_registry.cc:157)
UATHelper: Packaging (Android (ASTC)): >>>               lb_policy_registry.cc.o:(grpc_core::LoadBalancingPolicyRegistry::ParseLoadBalancingConfig(grpc_core::Json const&, grpc_error**)) in archive C:/Program Files/Epic Games/UE_5.4/Engine/Plugins/Marketplace/Convai_5.4/Source/ThirdParty/gRPC/lib/android/arm64-v8a/libgrpc.a
UATHelper: Packaging (Android (ASTC)): >>> referenced 39 more times
UATHelper: Packaging (Android (ASTC)): ld.lld: error: too many errors emitted, stopping now (use -error-limit=0 to see all errors)
UATHelper: Packaging (Android (ASTC)): clang++: error: linker command failed with exit code 1 (use -v to see invocation)
UATHelper: Packaging (Android (ASTC)): Total time in Parallel executor: 13.05 seconds
UATHelper: Packaging (Android (ASTC)): Total execution time: 19.16 seconds
UATHelper: Packaging (Android (ASTC)): Took 19.78s to run dotnet.exe, ExitCode=6
PackagingResults: Error: too many errors emitted, stopping now (use -error-limit=0 to see all errors)
PackagingResults: Error: linker command failed with exit code 1 (use -v to see invocation)
UATHelper: Packaging (Android (ASTC)): UnrealBuildTool failed. See log for more details. (C:\Users\jonat\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_5.4\UBA-leeds_rhinos-Android-Shipping.txt)
UATHelper: Packaging (Android (ASTC)): AutomationTool executed for 0h 0m 21s
UATHelper: Packaging (Android (ASTC)): AutomationTool exiting with ExitCode=6 (6)
UATHelper: Packaging (Android (ASTC)): BUILD FAILED
PackagingResults: Error: Unknown Error

gtree · October 29, 2025, 5:41pm

Is this helpful? Does anyone have any ideas? Thanks

K3 · October 29, 2025, 5:43pm

We will look into it and get back to you.

gtree · October 30, 2025, 12:40pm

Hello

Is this fixable or do I need to look at alternatives?

Thanks

K3 · October 30, 2025, 1:05pm

Which version of the Convai plugin are you using? Additionally, are you running on Linux?

K3 · October 30, 2025, 1:26pm

Go to your plugin directory: Source → ThirdParty → gRPC → lib → android, then replace the arm64-v8a folder with this.

gtree · October 30, 2025, 2:17pm

hi

I have tried replacing the arm64-v8a folder with the files you gave me but still getting the same link errors.

I am building on Win 11 - not Linux. I am using the latest version downloaded via fab. I have also tried using from release 3.1.4 on github and even building from scratch but always get same errors.

K3 · October 30, 2025, 2:37pm

3.1.4 is a very old version. Please use the latest version. Releases · Conv-AI/Convai-UnrealEngine-SDK · GitHub

gtree · October 30, 2025, 2:50pm

Thanks for clarifying — maybe I wasn’t being clear enough earlier.

I’m currently using version 3.6.7, which I’ve downloaded both from the Fab store and GitHub. Neither build works when targeting Android (ASTC, arm64).

To troubleshoot, I’ve:

Tested every version from 3.1.4 up to 3.6.7, all producing the same Abseil/gRPC undefined symbol errors during linking.
Followed both build methods described in the GitHub README to rebuild the plugin from source.
Replaced the arm64-v8a folder with the files you provided — unfortunately, still getting the same linker errors.

If there’s a specific version of the gRPC/Abseil static libraries that the current Convai plugin expects, or a confirmed working NDK version, that would really help narrow this down.

K3 · October 30, 2025, 11:10pm

Thanks for the details. A short-term fix for these specific Android build settings isn’t feasible on our side right now. We’re actively working on a new update that we’ll announce soon, and it is expected to resolve gRPC-related issues automatically.

gtree · October 30, 2025, 11:12pm

May I ask - are you experiencing these issues?

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Android build fails with Abseil/GRPC undefined symbols from Convai 5.4 plugin

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