Gentoo's Bugzilla –
Attachment 423612 Details for
Bug 572626[sage-on-gentoo] sci-mathematics/singular-3.1.7_p1-r4 - /usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/include/g++-v5/bits/c++0x_warning.h:32:2: error: #error This file requires compiler and library support for the ISO C++ 2011 standard.