Hi I'm trying to install boost 1.47 in a single threaded edition but it does not seems to work. Here is what I tried: ./bootstrap.sh --without-icu --without-libraries=graph_parallel,mpi,python ./b2 threading=single --layout=system --prefix=/usr/local Here is the error I got on the second command: Building the Boost C++ Libraries. Performing configuration checks - has_icu builds : yes - ../config//has_gcc_visibility builds : yes - ../config//has_long_double_support builds : yes /storage/src/boost_1_47_0/tools/build/v2/build/virtual-target.jam:1079: in virtual-target.register-actual-name from module virtual-target error: Duplicate name of actual target: <pstage/lib>libboost_system.so.1.47.0 error: previous virtual target { common%common.copy-libboost_system.so.1.47.0.SHARED_LIB { gcc%gcc.link.dll-libboost_system.so.1.47.0.SHARED_LIB { gcc%gcc.compile.c++-error_code.o.OBJ { error_code.cpp.CPP } } } } error: created from ./stage-proper error: another virtual target { common%common.copy-libboost_system.so.1.47.0.SHARED_LIB { gcc%gcc.link.dll-libboost_system.so.1.47.0.SHARED_LIB { gcc%gcc.compile.c++-error_code.o.OBJ { error_code.cpp.CPP } } } } error: created from ./stage-proper error: added properties: <threading>single <warnings>on error: removed properties: <threading>multi <warnings>all /storage/src/boost_1_47_0/tools/build/v2/build/virtual-target.jam:490: in actualize-no-scanner from module object(file-target)@2784 /storage/src/boost_1_47_0/tools/build/v2/build/virtual-target.jam:135: in object(file-target)@2784.actualize from module object(file-target)@2784 /storage/src/boost_1_47_0/tools/build/v2/build-system.jam:749: in load from module build-system /storage/src/boost_1_47_0/tools/build/v2/kernel/modules.jam:283: in import from module modules /storage/src/boost_1_47_0/tools/build/v2/kernel/bootstrap.jam:142: in boost-build from module /storage/src/boost_1_47_0/boost-build.jam:17: in module scope from module Is there anything I can do to fix this locally ?? Best regards Allan W. Nielsen