linking failure

[info] Compiling to native code (3498 ms)
[error] clang-5.0: warning: -Wl,-lc++abi: 'linker' input unused [-Wunused-command-line-argument]
[error] clang-5.0: warning: argument unused during compilation: '-stdlib=libc++' [-Wunused-command-line-argument]
[error] clang-5.0: warning: -Wl,-lc++abi: 'linker' input unused [-Wunused-command-line-argument]
[error] clang-5.0: warning: argument unused during compilation: '-stdlib=libc++' [-Wunused-command-line-argument]
[error] clang-5.0: warning: -Wl,-lc++abi: 'linker' input unused [-Wunused-command-line-argument]
[error] clang-5.0: warning: argument unused during compilation: '-stdlib=libc++' [-Wunused-command-line-argument]
[error] clang-5.0: warning: -Wl,-lc++abi: 'linker' input unused [-Wunused-command-line-argument]
[error] clang-5.0: warning: argument unused during compilation: '-stdlib=libc++' [-Wunused-command-line-argument]
[error] target/scala-2.11/native/lib/optional/re2.cpp.o: In function `scalanative_cre2_find_named_capturing_groups':
[error] target/scala-2.11/native/lib/optional/re2.cpp:(.text+0x39f): undefined reference to `re2::RE2::NamedCapturingGroups() const'
[error] target/scala-2.11/native/lib/optional/re2.cpp.o: In function `scalanative_cre2_replace_re':
[error] target/scala-2.11/native/lib/optional/re2.cpp:(.text+0x856): undefined reference to `re2::RE2::Replace(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*, re2::RE2 const&, re2::StringPiece const&)'
[error] target/scala-2.11/native/lib/optional/re2.cpp.o: In function `scalanative_cre2_global_replace_re':
[error] target/scala-2.11/native/lib/optional/re2.cpp:(.text+0x9e4): undefined reference to `re2::RE2::GlobalReplace(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*, re2::RE2 const&, re2::StringPiece const&)'
[error] target/scala-2.11/native/lib/optional/re2.cpp.o: In function `scalanative_cre2_quote_meta':
[error] target/scala-2.11/native/lib/optional/re2.cpp:(.text+0xb09): undefined reference to `re2::RE2::QuoteMeta(re2::StringPiece const&)'