Something

C:\blender\build\win32-mingw\lib\libblender_bop.a(BOP_Segment.o):BOP_Segment.cpp
:(.text+0x3f0): undefined reference to `std::basic_ostream<char, std::char_trait
s<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, st
d::char_traits<char> >&, char const*)'
C:\blender\build\win32-mingw\lib\libblender_bop.a(BOP_Segment.o):BOP_Segment.cpp
:(.text+0x3ff): undefined reference to `std::ostream::operator<<(unsigned long)'

C:\blender\build\win32-mingw\lib\libblender_bop.a(BOP_Segment.o):BOP_Segment.cpp
:(.text+0x410): undefined reference to `std::basic_ostream<char, std::char_trait
s<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, st
d::char_traits<char> >&, char const*)'
C:\blender\build\win32-mingw\lib\libblender_bop.a(BOP_Segment.o):BOP_Segment.cpp
:(.text+0x45c): undefined reference to `std::ios_base::Init::Init()'
C:\blender\build\win32-mingw\lib\libblender_bop.a(BOP_Segment.o):BOP_Segment.cpp
:(.text+0x478): undefined reference to `std::ios_base::Init::~Init()'
C:\blender\build\win32-mingw\lib\libblender_bop.a(BOP_Splitter.o):BOP_Splitter.c
pp:(.text+0x51c): undefined reference to `std::ios_base::Init::Init()'
C:\blender\build\win32-mingw\lib\libblender_bop.a(BOP_Splitter.o):BOP_Splitter.c
pp:(.text+0x538): undefined reference to `std::ios_base::Init::~Init()'
collect2: ld returned 1 exit status

=====
scons: *** [C:\blender\build\win32-mingw\bin\blender.exe] Error 1
scons: building terminated because of errors.
C:\blender\blender>