我尝试从端口（curl-7.37.1_2）安装最新的curl更新并启用HTTP/2.0支持，并且我需要为此目的构建spdylay，但我不断收到以下奇怪的错误，并且无法在任何地方找到有关它们的信息：
spdylay_ssl.o: In function `spdylay::connect_to(std::string const&, unsigned short)':
spdylay_ssl.cc:(.text+0x328): undefined reference to `std::ctype<char>::_M_widen_init() const'
spdylay_ssl.o: In function `spdylay::make_listen_socket(std::string const&, unsigned short, int)':
spdylay_ssl.cc:(.text+0x56e): undefined reference to `std::ctype<char>::_M_widen_init() const'
spdylay_ssl.o: In function `spdylay::ssl_handshake(ssl_st*, int)':
spdylay_ssl.cc:(.text+0xa25): undefined reference to `std::ctype<char>::_M_widen_init() const'
spdylay_ssl.cc:(.text+0xabf): undefined reference to `std::ctype<char>::_M_widen_init() const'
spdylay_ssl.o: In function `spdylay::nonblock_connect_to(std::string const&, unsigned short, int)':
spdylay_ssl.cc:(.text+0x1018): undefined reference to `std::ctype<char>::_M_widen_init() const'
spdylay_ssl.o:spdylay_ssl.cc:(.text+0x1214): more undefined references to `std::ctype<char>::_M_widen_init() const' follow
collect2: error: ld returned 1 exit status
*** [spdycat] Error code 1
我该如何解决这个问题？
FreeBSD 9.2 x86_64
gcc version 4.9.2 20140820
OpenSSL 1.0.1i 6 Aug 2014
CC=gcc49
CXX=g++49
CPP=cpp49
CFLAGS+=-mssse3
WITH_PKGNG=yes
WITH_OPENSSL_PORT=yes