"Optimization flag is not supported" build failure(s) — clang 4.0.1

PackageVersionSupposed error messageFull log Bug report
libi8x 0.0.3-1clang: error: optimization flag '-fno-gcse' is not supported [-Werror,-Wignored-optimization-argument] Log
libv8-3.14 3.14.5.8-11clang: error: optimization flag '-fno-delete-null-pointer-checks' is not supported [-Werror,-Wignored-optimization-argument] Log
pesign 0.112-4clang: error: optimization flag '-fno-merge-constants' is not supported [-Werror,-Wignored-optimization-argument] Log

3 errors