Gentoo's Bugzilla –
Attachment 346376 Details for
Bug 458338dev-libs/boost-1.49.0-r2 with sys-libs/uclibc - In file included from libs/locale/src/posix/codecvt.cpp:13:0: libs/locale/src/posix/all_generator.hpp:25:59: error: 'locale_t' was not declared in this scope