error: "<experimental/string_view> has been removed. Use <string_view> instead."

[berlin2017]

FAILURE: Build failed with an exception.

• What went wrong: Execution failed for task ':main:externalNativeBuildNoovpn3Debug'.

  Build command failed. Error while executing process C:\Users\berlin\AppData\Local\Android\Sdk\cmake\3.6.4111459\bin\cmake.exe with arguments {--build D:\WORK\android\vpn\ics-openvpn\main.externalNativeBuild\cmake\noovpn3Debug\arm64-v8a --target ovpn3} [1/2] Building CXX object CMakeFiles/ovpn3.dir/openvpn3/client/ovpncli.cpp.o FAILED: C:\Users\berlin\AppData\Local\Android\Sdk\ndk-bundle\toolchains\llvm\prebuilt\windows-x86_64\bin\clang++.exe --target=aarch64-none-linux-android21 --gcc-toolchain=C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/toolchains/aarch64-linux-android-4.9/prebuilt/windows-x86_64 --sysroot=C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sysroot -DASIO_STANDALONE -DGIT_VERSION_STRING=\"icsopenvpn/v0.7.6-0-gc38c7a0b\" -DHAVE_CONFIG_H -DHAVE_LZ4 -DHAVE_LZO -DNO_ROUTE_EXCLUDE_EMULATION -DOPENVPN_SHOW_SESSION_TOKEN -DUSE_ASIO -DUSE_OPENSSL -Dovpn3_EXPORTS -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/lzo/include -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3 -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3/client -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/mbedtls/include -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/crypto/include -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openssl/include -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openssl/crypto/include -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openssl -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openssl/crypto -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openssl/crypto/ec/curve448/arch_32 -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openssl/crypto/ec/curve448 -ID:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/lz4/lib -isystem C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include -isystem C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++abi/include -isystem C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sysroot/usr/include/aarch64-linux-android -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -Wa,--noexecstack -Wformat -Werror=format-security -std=c++11 -O0 -fno-limit-debug-info -fPIC -std=c++1y -MD -MT CMakeFiles/ovpn3.dir/openvpn3/client/ovpncli.cpp.o -MF CMakeFiles\ovpn3.dir\openvpn3\client\ovpncli.cpp.o.d -o CMakeFiles/ovpn3.dir/openvpn3/client/ovpncli.cpp.o -c D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:21: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/basic_datagram_socket.hpp:20: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/basic_socket.hpp:40: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/reactive_socket_service.hpp:22: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/buffer.hpp:27: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/string_view.hpp:25: C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\experimental/string_view:11:2: error: "<experimental/string_view> has been removed. Use instead."

  error "<experimental/string_view> has been removed. Use instead."

  ^ In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:21: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/basic_datagram_socket.hpp:20: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/basic_socket.hpp:40: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/reactive_socket_service.hpp:22: In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/buffer.hpp:27: D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/string_view.hpp:36:12: error: no member named 'experimental' in namespace 'std' using std::experimental::basic_string_view;

  
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/string_view.hpp:37:12: error: no member named 'experimental' in namespace 'std'
  using std::experimental::string_view;
  ~~~~~^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:21:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/basic_datagram_socket.hpp:20:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/basic_socket.hpp:40:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/reactive_socket_service.hpp:22:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/buffer.hpp:1488:5: error: no template named 'basic_string_view'; did you mean 'std::basic_string_view'?
  basic_string_view<Elem, Traits> data) ASIO_NOEXCEPT
  ^~~~~~~~~~~~~~~~~
  std::basic_string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:194:28: note: 'std::basic_string_view' declared here
  class _LIBCPP_TEMPLATE_VIS basic_string_view {
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:21:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/basic_datagram_socket.hpp:20:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/basic_socket.hpp:40:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/reactive_socket_service.hpp:22:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/buffer.hpp:1509:5: error: no template named 'basic_string_view'; did you mean 'std::basic_string_view'?
  basic_string_view<Elem, Traits> data,
  ^~~~~~~~~~~~~~~~~
  std::basic_string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:194:28: note: 'std::basic_string_view' declared here
  class _LIBCPP_TEMPLATE_VIS basic_string_view {
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:24:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v4.hpp:287:38: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  ASIO_DECL address_v4 make_address_v4(string_view str);
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:24:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v4.hpp:294:5: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  string_view str, asio::error_code& ec);
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:24:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v4.hpp:326:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/impl/address_v4.ipp:192:28: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  address_v4 make_address_v4(string_view str)
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:24:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v4.hpp:326:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/impl/address_v4.ipp:197:28: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  address_v4 make_address_v4(string_view str,
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:25:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v6.hpp:276:38: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  ASIO_DECL address_v6 make_address_v6(string_view str);
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:25:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v6.hpp:283:5: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  string_view str, asio::error_code& ec);
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:25:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v6.hpp:333:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/impl/address_v6.ipp:308:28: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  address_v6 make_address_v6(string_view str)
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:25:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address_v6.hpp:333:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/impl/address_v6.ipp:313:28: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  address_v6 make_address_v6(string_view str,
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:217:32: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  ASIO_DECL address make_address(string_view str);
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/address.hpp:225:5: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  string_view str, asio::error_code& ec);
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address.hpp:257:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/impl/address.ipp:139:22: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  address make_address(string_view str)
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:70:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/address.hpp:257:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/impl/address.ipp:144:22: error: unknown type name 'string_view'; did you mean 'std::string_view'?
  address make_address(string_view str,
  ^~~~~~~~~~~
  std::string_view
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:79:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/basic_resolver.hpp:27:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/basic_resolver_iterator.hpp:27:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/basic_resolver_entry.hpp:53:7: error: no type named 'string_view' in namespace 'asio'; did you mean 'std::string_view'?
  ASIO_STRING_VIEW_PARAM host, ASIO_STRING_VIEW_PARAM service)
  ^~~~~~~~~~~~~~~~~~~~~~
  std::string_view
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/string_view.hpp:42:33: note: expanded from macro 'ASIO_STRING_VIEW_PARAM'
  # define ASIO_STRING_VIEW_PARAM asio::string_view
  ^~~~~~
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  In file included from D:\WORK\android\vpn\ics-openvpn\main\src\main\cpp\openvpn3\client\ovpncli.cpp:30:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/openvpn3\openvpn/io/io.hpp:28:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio.hpp:79:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include/asio/ip/basic_resolver.hpp:27:
  In file included from D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/basic_resolver_iterator.hpp:27:
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/ip/basic_resolver_entry.hpp:53:36: error: no type named 'string_view' in namespace 'asio'; did you mean 'std::string_view'?
  ASIO_STRING_VIEW_PARAM host, ASIO_STRING_VIEW_PARAM service)
  ^~~~~~~~~~~~~~~~~~~~~~
  std::string_view
  D:/WORK/android/vpn/ics-openvpn/main/src/main/cpp/asio/asio/include\asio/detail/string_view.hpp:42:33: note: expanded from macro 'ASIO_STRING_VIEW_PARAM'
  # define ASIO_STRING_VIEW_PARAM asio::string_view
  ^~~~~~
  C:/Users/berlin/AppData/Local/Android/Sdk/ndk-bundle/sources/cxx-stl/llvm-libc++/include\string_view:770:37: note: 'std::string_view' declared here
  typedef basic_string_view<char>     string_view;
  ^
  fatal error: too many errors emitted, stopping now [-ferror-limit=]
  20 errors generated.
  ninja: build stopped: subcommand failed.

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BUILD FAILED in 7s 23 actionable tasks: 5 executed, 18 up-to-date

[schwabe]

Already fixed in newer commits.

[berlin2017]

Already fixed in newer commits.

why I also have this issue？android studio 3.2.1 ndk18.1 cmake 3.6 swigwin-3.0.12 my partner build success with mac os

[schwabe]

No idea. Your asio submodule not updated or different build enviornment on your side. I already fixed that exact error in my environment with one of the newer commits.