Okay, I gave compiling the beta 1 another shot, as follows: ./bootstrap.sh --prefix=/home/martin/app/boost/installation --with-icu=/home/martin/app/icu/installation ./b2 -sICU_PATH=/home/martin/app/icu/installation install >out.b2.install 2>&1 & the b2 output then does start as follows: Performing configuration checks - has_icu builds : yes warning: Graph library does not contain MPI-based parallel components. note: to enable them, add "using mpi ;" to your user-config.jam - iconv (libc) : yes - icu : yes ... but then later on there are compilation errors in Boost.Locale, such as:

In file included from libs/locale/src/icu/formatter.cpp:25:0: libs/locale/src/icu/predefined_formatters.hpp: In member function ‘icu_48::NumberFormat* boost::locale::impl_icu::icu_formatters_cache::number_format(boost::locale::impl_icu::icu_formatters_cache::fmt_type) const’: libs/locale/src/icu/predefined_formatters.hpp:127:61: error: ‘URBNF_SPELLOUT’ was not declared in this scope libs/locale/src/icu/predefined_formatters.hpp:127:61: note: suggested alternative: /home/martin/app/icu/installation/include/unicode/rbnf.h:49:5: note: ‘icu_48::URBNF_SPELLOUT’ libs/locale/src/icu/predefined_formatters.hpp:130:61: error: ‘URBNF_ORDINAL’ was not declared in this scope libs/locale/src/icu/predefined_formatters.hpp:130:61: note: suggested alternative: /home/martin/app/icu/installation/include/unicode/rbnf.h:50:5: note: ‘icu_48::URBNF_ORDINAL’

"g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_LOCALE_DYN_LINK=1 -DBOOST_LOCALE_NO_WINAPI_BACKEND=1 -DBOOST_LOCALE_WITH_ICONV=1 -DBOOST_LOCALE_WITH_ICU=1 -DBOOST_THREAD_NO_LIB=1 -DBOOST_THREAD_POSIX -DBOOST_THREAD_USE_DLL=1 -DNDEBUG -I"." -I"/home/martin/app/icu/installation/include" -c -o "bin.v2/libs/locale/build/gcc-4.6.1/release/threading-multi/icu/formatter.o" "libs/locale/src/icu/formatter.cpp"

The above errors are probably caused because I did what ICU recommends you do (for the first time ever), which is: -# define U_USING_ICU_NAMESPACE 1 + // Set to 0 to force namespace declarations in ICU usage. +# define U_USING_ICU_NAMESPACE 0in the ICU unicode/uversion.h file The above is advised in ICU 's readme.html in the How To Build And Install ICU / Recommended Build Options section... Has that advice become incorrect in recent ICU versions, perhaps?