https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109818
--- Comment #27 from Janez Zemva <janezz55 at gmail dot com> --- forcing glibcxx_cv_c99_math_tr1=yes solved this issue for me. The C99 compliance test is really strict, even openlibm fails the test (it fails to define float_t and double_t, but this can be hacked around).
