Hi, The trunk version of Boost.Thread compiles with GCC-MinGW64 but the release branch does not[1]. Is the trunk version going to be merged to release for 1.47.0? Cheers, Mikko [1] Here's the error log: gcc.compile.c++ bin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi/win32/thread.o "/usr/bin/x86_64-w64-mingw32-g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -mthreads -Wno-long-long -DBOOST_ALL_NO_LIB=1 -DBOOST_THREAD_BUILD_LIB=1 -DNDEBUG -I"." -c -o "bin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi/win32/thread.o" "libs/thread/src/win32/thread.cpp" In file included from ./boost/thread/win32/basic_timed_mutex.hpp:14:0, from ./boost/thread/win32/mutex.hpp:8, from ./boost/thread/mutex.hpp:14, from ./boost/thread/detail/thread.hpp:13, from ./boost/thread/thread.hpp:22, from libs/thread/src/win32/thread.cpp:10: ./boost/thread/win32/interlocked_read.hpp: In function 'void* boost::detail::interlocked_read_acquire(void* volatile*)': ./boost/thread/win32/interlocked_read.hpp:63:20: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] ./boost/thread/win32/interlocked_read.hpp: In function 'void boost::detail::interlocked_write_release(void* volatile*, void*)': ./boost/thread/win32/interlocked_read.hpp:71:13: error: cast from 'void*' to 'long int' loses precision [-fpermissive] ./boost/thread/win32/interlocked_read.hpp:71:13: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] In file included from ./boost/thread/win32/mutex.hpp:8:0, from ./boost/thread/mutex.hpp:14, from ./boost/thread/detail/thread.hpp:13, from ./boost/thread/thread.hpp:22, from libs/thread/src/win32/thread.cpp:10: ./boost/thread/win32/basic_timed_mutex.hpp: In member function 'void boost::detail::basic_timed_mutex::destroy()': ./boost/thread/win32/basic_timed_mutex.hpp:46:39: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] In file included from ./boost/thread/win32/mutex.hpp:8:0, from ./boost/thread/mutex.hpp:14, from ./boost/thread/detail/thread.hpp:13, from ./boost/thread/thread.hpp:22, from libs/thread/src/win32/thread.cpp:10: ./boost/thread/win32/basic_timed_mutex.hpp: In member function 'void* boost::detail::basic_timed_mutex::get_event()': ./boost/thread/win32/basic_timed_mutex.hpp:183:43: error: cast from 'void*' to 'long int' loses precision [-fpermissive] ./boost/thread/win32/basic_timed_mutex.hpp:183:43: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] In file included from ./boost/thread/shared_mutex.hpp:14:0, from ./boost/thread/detail/thread_group.hpp:9, from ./boost/thread/thread.hpp:24, from libs/thread/src/win32/thread.cpp:10: ./boost/thread/win32/shared_mutex.hpp: In member function 'T boost::shared_mutex::interlocked_compare_exchange(T*, T, T) [with T = boost::shared_mutex::state_data]': ./boost/thread/win32/shared_mutex.hpp:110:103: instantiated from here ./boost/thread/win32/shared_mutex.hpp:50:99: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] ./boost/thread/win32/shared_mutex.hpp:50:99: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] ./boost/thread/win32/shared_mutex.hpp:51:52: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] ./boost/thread/win32/shared_mutex.hpp:51:52: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] ...failed gcc.compile.c++ bin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi/win32/thread.o... ...skipped <pbin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi>libboost_thread_win32-mgw46-mt-1_47.a(clean) for lack of <pbin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi>win32/thread.o... ...skipped <pbin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi>libboost_thread_win32-mgw46-mt-1_47.a for lack of <pbin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi>win32/thread.o... ...skipped <pstage/lib>libboost_thread_win32-mgw46-mt-1_47.a for lack of <pbin.v2/libs/thread/build/gcc-mingw-4.6.1/release/link-static/target-os-windows/threadapi-win32/threading-multi>libboost_thread_win32-mgw46-mt-1_47.a... ...failed updating 1 target...