I built Boost_1_59_0_b1_rc1 with no apparent errors. Here are the specifics: Windows 7.1, 64-bit, fully patched; MinGW 5.1.0 64-bit. Time to build: 2:59:00 (I was browsing while waiting) Build command line: \bin\b2.exe --prefix=d:\boost_1_59_0_b1 --build-type=complete --without-mpi cxxflags="-std=c++11" -a toolset=gcc stage >d:\bin\build.log 2>&1 Highlights of build log: Performing configuration checks - 32-bit : no - 64-bit : yes - arm : no - mips1 : no - power : no - sparc : no - x86 : yes - has_icu builds : no warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - zlib : yes - iconv (libc) : no - iconv (separate) : yes - icu : no - icu (lib64) : no - g++ -shared-* supported : no - compiler-supports-visibility : yes - message-compiler : no - compiler-supports-ssse3 : yes - compiler-supports-avx2 : yes - gcc visibility : yes - long double support : yes . . . Component configuration: - atomic : building - chrono : building - container : building - context : building - coroutine : building - date_time : building - exception : building - filesystem : building - graph : building - graph_parallel : building - iostreams : building - locale : building - log : building - math : building - mpi : not building - program_options : building - python : building - random : building - regex : building - serialization : building - signals : building - system : building - test : building - thread : building - timer : building - wave : building ...patience... ...patience... ...patience... ...patience... ...patience... ...found 16476 targets... ...updating 5881 targets... <all that other log stuff> ...failed updating 340 targets... ...skipped 104 targets... ...updated 5437 targets... My project compiled and linked as normal. Merrill Cornish **