I'm trying to build boost_1_34_0 on an x86_64 linux box with a 32-bit address model. After letting configure create a bjam for me, I have tried many variations on the following: tools/jam/src/bin.linux/bjam address-model=64 -d2 release And also: tools/jam/src/bin.linux/bjam cxxflags=-m32 linkflags=-m32 cflags=-m32 -d2 release The -d2 appears to show me what the compiler is doing. I see no sign of -m32 command-line options when the compiler is invoked. I also checked the .so file that was created and verifited that it's dynamically linked to libraries in /lib64. What am I doing wrong?? Here's some of the -d2 output with address-model: salmonj@drdws032.nyc$ tools/jam/src/bin.linux/bjam address-model=32 -d2 release Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (don't panic: this is a strictly optional feature). warning: No toolsets are configured. warning: Configuring default toolset "gcc". warning: If the default is wrong, you may not be able to build C++ programs. warning: Use the "--toolset=xxxxx" option to override our guess. warning: For more configuration options, please consult warning: http://boost.org/boost-build2/doc/html/bbv2/advanced/configuration.html ...patience... ...patience... ...found 4006 targets... ...updating 756 targets... gcc.compile.c++ bin.v2/libs/python/build/gcc-3.4.4/release/address-model-32/threading-multi/type_id.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -fPIC -pthread -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/usr/include/python2.3" -c -o "bin.v2/libs/python/build/gcc-3.4.4/release/address-model-32/threading-multi/type_id.o" "libs/python/src/converter/type_id.cpp" gcc.compile.c++ bin.v2/libs/python/build/gcc-3.4.4/release/address-model-32/threading-multi/enum.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -fPIC -pthread -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/usr/include/python2.3" -c -o "bin.v2/libs/python/build/gcc-3.4.4/release/address-model-32/threading-multi/enum.o" "libs/python/src/object/enum.cpp" And here's some more with cxxflags/cflags/linkflags: salmonj@drdws032.nyc$ tools/jam/src/bin.linux/bjam cflags=32 cxxflags=-m32 linkflags=-m32 -d2 release Building Boost.Regex with the optional Unicode/ICU support disabled. Please refer to the Boost.Regex documentation for more information (don't panic: this is a strictly optional feature). warning: No toolsets are configured. warning: Configuring default toolset "gcc". warning: If the default is wrong, you may not be able to build C++ programs. warning: Use the "--toolset=xxxxx" option to override our guess. warning: For more configuration options, please consult warning: http://boost.org/boost-build2/doc/html/bbv2/advanced/configuration.html ...patience... ...patience... ...found 3994 targets... ...updating 747 targets... MkDir1 bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi mkdir "bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi" gcc.compile.c++ bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi/numeric.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -fPIC -pthread -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/usr/include/python2.3" -c -o "bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi/numeric.o" "libs/python/src/numeric.cpp" gcc.compile.c++ bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi/list.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -fPIC -pthread -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/usr/include/python2.3" -c -o "bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi/list.o" "libs/python/src/list.cpp" gcc.compile.c++ bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi/long.o "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -fPIC -pthread -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/usr/include/python2.3" -c -o "bin.v2/libs/python/build/gcc-3.4.4/release/threading-multi/long.o" "libs/python/src/long.cpp"