C++ 为什么会出现这种构建错误？

我尝试使用cygwin在Win 8.1上构建hydra，但在运行make时出现以下构建错误：

   -DHAVE_MATH_H
hydra-pop3.o:hydra-pop3.c:(.text+0x697): undefined reference to `MD5_Init'
hydra-pop3.o:hydra-pop3.c:(.text+0x697): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `MD5_Init'
hydra-pop3.o:hydra-pop3.c:(.text+0x6f2): undefined reference to `MD5_Update'
hydra-pop3.o:hydra-pop3.c:(.text+0x6f2): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `MD5_Update'
hydra-pop3.o:hydra-pop3.c:(.text+0x70d): undefined reference to `MD5_Update'
hydra-pop3.o:hydra-pop3.c:(.text+0x70d): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `MD5_Update'
hydra-pop3.o:hydra-pop3.c:(.text+0x71e): undefined reference to `MD5_Final'
hydra-pop3.o:hydra-pop3.c:(.text+0x71e): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `MD5_Final'
/usr/lib/gcc/x86_64-pc-cygwin/4.8.2/../../../../x86_64-pc-cygwin/bin/ld: hydra-pop3.o: bad reloc address 0x0 in section `.pdata'
/usr/lib/gcc/x86_64-pc-cygwin/4.8.2/../../../../x86_64-pc-cygwin/bin/ld: final link failed: Invalid operation
collect2: error: ld returned 1 exit status
Makefile:51: recipe for target 'hydra' failed
make: *** [hydra] Error 1

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可以做些什么？我可以运行./configure，但运行make失败

检查LIB_路径，需要包含LIB文件导出的“MD5_Init”函数