Please see http://tinyurl.com/5f7ba "C:\Comeau\libcomo\cnames\cstring", line 31: error #247: function "std::strlen" has already been defined extern "C++" inline size_t strlen(const char *arg) { return ::strlen(arg); } ^ "C:\Comeau\libcomo\cnames\cstring", line 31: error #247: function "std::strlen" has already been defined extern "C++" inline size_t strlen(const char *arg) { return ::strlen(arg); } ^ 2 errors detected in the compilation of "..\libs\multi_index\test\test_basic_main.cpp". The problem has nothing to do with Boost.MultiIndex, actually, as test_basic_main.cpp does not do anything more than including <boost/test/included/test_exec_monitor.hpp> These tests used to pass one or two days ago. I've inspected Boost.Test for recent changes and found none. Other libraries are affected by this problem: algorithm/minmax algorithm/string program_options ... Thanks Joaquín M López Muñoz Telefónica, Investigación y Desarrollo