Building Boost.Regex with Unicode/ICU support enabled
Using ICU in /usr/include
...patience...
...found 505 targets...
...updating 18 targets...
gcc.compile.c++ /build/bjam/boost_1.37.0/libs/regex/build/gcc-4.3/debug/c_regex_traits.o
/bin/sh: line 1: target-os: No such file or directory

    "/opt/icecream/bin/g++"  -ftemplate-depth-128 -m64 -O0 -fno-inline -Wall -g -fPIC -pthread  -DBOOST_ALL_NO_LIB=1 -DBOOST_HAS_ICU=1 <target-os>freebsd:<include>/usr/local/include -DBOOST_REGEX_DYN_LINK=1  -I"/rmc/hunold/packages/boost" -c -o "/build/bjam/boost_1.37.0/libs/regex/build/gcc-4.3/debug/c_regex_traits.o" "/rmc/hunold/packages/boost/libs/regex/src/../src/c_regex_traits.cpp"

...failed gcc.compile.c++ /build/bjam/boost_1.37.0/libs/regex/build/gcc-4.3/debug/c_regex_traits.o...
...failed updating 1 target...