Clean default install on OSX system with OpenMPI installed claims MPI is building, but does not build MPI component by default - it's a little confusing... ./bjam Building the Boost C++ Libraries. ...found 14 targets... ...updating 8 targets... common.mkdir bin.v2 common.mkdir bin.v2/libs common.mkdir bin.v2/libs/regex common.mkdir bin.v2/libs/regex/build common.mkdir bin.v2/libs/regex/build/darwin-4.2.1 common.mkdir bin.v2/libs/regex/build/darwin-4.2.1/debug darwin.compile.c++ bin.v2/libs/regex/build/darwin-4.2.1/debug/has_icu_test.o libs/regex/build/has_icu_test.cpp:12:30: error: unicode/uversion.h: No such file or directory libs/regex/build/has_icu_test.cpp:13:28: error: unicode/utypes.h: No such file or directory libs/regex/build/has_icu_test.cpp:14:27: error: unicode/uchar.h: No such file or directory libs/regex/build/has_icu_test.cpp:15:26: error: unicode/coll.h: No such file or directory libs/regex/build/has_icu_test.cpp: In function ‘int main()’: libs/regex/build/has_icu_test.cpp:23: error: ‘UErrorCode’ was not declared in this scope libs/regex/build/has_icu_test.cpp:23: error: expected `;' before ‘err’ libs/regex/build/has_icu_test.cpp:24: error: ‘UChar32’ was not declared in this scope libs/regex/build/has_icu_test.cpp:24: error: expected `;' before ‘c’ libs/regex/build/has_icu_test.cpp:25: error: ‘err’ was not declared in this scope "g++" -ftemplate-depth-128 -O0 -fno-inline -Wall -pedantic -g -dynamic -no-cpp-precomp -gdwarf-2 -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_HAS_ICU=1 -I"." -c -o "bin.v2/libs/regex/build/darwin-4.2.1/debug/has_icu_test.o" "libs/regex/build/has_icu_test.cpp" ...failed darwin.compile.c++ bin.v2/libs/regex/build/darwin-4.2.1/debug/has_icu_test.o... ...skipped <pbin.v2/libs/regex/build/darwin-4.2.1/debug>has_icu for lack of <pbin.v2/libs/regex/build/darwin-4.2.1/debug>has_icu_test.o... ...failed updating 1 target... ...skipped 1 target... ...updated 6 targets... Performing configuration checks - 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 ...found 7 targets... ...updating 5 targets... common.mkdir bin.v2/libs/math common.mkdir bin.v2/libs/math/config common.mkdir bin.v2/libs/math/config/darwin-4.2.1 common.mkdir bin.v2/libs/math/config/darwin-4.2.1/debug darwin.compile.c++ bin.v2/libs/math/config/darwin-4.2.1/debug/has_gcc_visibility.o ...updated 5 targets... - ../config//has_gcc_visibility builds : yes ...found 47 targets... ...updating 1 target... darwin.compile.c++ bin.v2/libs/math/config/darwin-4.2.1/debug/has_long_double_support.o ...updated 1 target... - ../config//has_long_double_support builds : yes warning: skipping optional Message Passing Interface (MPI) library. note: to enable MPI support, add "using mpi ;" to user-config.jam. note: to suppress this message, pass "--without-mpi" to bjam. note: otherwise, you can safely ignore this message. Component configuration: - date_time : building - exception : building - filesystem : building - graph : building - graph_parallel : building - iostreams : building - math : building - mpi : building - program_options : building - python : building - random : building - regex : building - serialization : building - signals : building - system : building - test : building - thread : building - wave : building