root@8790fc1eb791:/webrtc/src/out/Default# ninja -C . libsig
ninja: Entering directory `.'
[1/1] Regenerating ninja files
[2/2] SOLINK ./libsig.so
FAILED: libsig.so libsig.so.TOC
python "../../build/toolchain/gcc_solink_wrapper.py" --readelf="readelf" --nm="nm" --sofile="./libsig.so" --tocfile="./libsig.so.TOC" --output="./libsig.so" -- ../../third_party/llvm-build/Release+Asserts/bin/clang++ -shared -fPIC -Wl,-z,noexecstack -Wl,-z,now -Wl,-z,relro -Wl,-z,defs -Wl,--no-as-needed -lpthread -Wl,--as-needed -fuse-ld=lld -Wl,--icf=all -m64 -Werror -Wl,--gdb-index -Wl,--fatal-warnings -nostdlib++ --sysroot=../../build/linux/debian_stretch_amd64-sysroot -L../../build/linux/debian_stretch_amd64-sysroot/lib/x86_64-linux-gnu -Wl,-rpath-link=../../build/linux/debian_stretch_amd64-sysroot/lib/x86_64-linux-gnu -L../../build/linux/debian_stretch_amd64-sysroot/usr/lib/x86_64-linux-gnu -Wl,-rpath-link=../../build/linux/debian_stretch_amd64-sysroot/usr/lib/x86_64-linux-gnu -o "./libsig.so" -Wl,-soname="libsig.so" @"./libsig.so.rsp"
/webrtc/src/out/Default/../../third_party/llvm-build/Release+Asserts/bin/ld.lld: error: undefined symbol: std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(char const*, unsigned long)
>>> referenced by string:1571 (../../buildtools/third_party/libc++/trunk/include/string:1571)
>>> obj/examples/libsig/signaling.o:(driveai::signaling::Signaling::SignIn())
/webrtc/src/out/Default/../../third_party/llvm-build/Release+Asserts/bin/ld.lld: error: undefined symbol: std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()
>>> referenced by signaling.cc:12 (../../examples/peerconnection/client/signaling/signaling.cc:12)
>>> obj/examples/libsig/signaling.o:(driveai::signaling::Signaling::SignIn())
clang: error: linker command failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand failed.
root@8790fc1eb791:/webrtc/src/out/Default#