OS X + boost::chrono fail.

[wchan]

Boost 1.54 is installed
GCC is 4.7.3

checking boost/chrono.hpp usability... yes
checking boost/chrono.hpp presence... yes
checking for boost/chrono.hpp... yes
checking for the Boost chrono library... configure: error: cannot compile a test that uses Boost chrono

configure:17816: checking boost/chrono.hpp usability
configure:17816: g++ -c -g -O2 -std=c++11 -I/orange/include conftest.cpp >&5
configure:17816: $? = 0
configure:17816: result: yes
configure:17816: checking boost/chrono.hpp presence
configure:17816: g++ -E -I/orange/include conftest.cpp
configure:17816: $? = 0
configure:17816: result: yes
configure:17816: checking for boost/chrono.hpp
configure:17816: result: yes
configure:17843: checking for the Boost chrono library
configure:17885: g++ -c -g -O2 -std=c++11 -I/orange/include conftest.cpp >&5
conftest.cpp: In function 'int main()':
conftest.cpp:42:1: error: 'thread_clock' is not a member of 'boost::chrono'
conftest.cpp:42:29: error: expected ';' before 'd'
configure:17885: $? = 1