Bug#1128257 requested we drop the arch-specific build flags for armhf. But we found they are still needed to manage failure with NEON code on 32-bit ARM, and instead updated them to -march=armv7-a+fp However, the principle of not applying arch-specific build flags is still reasonable in general. We should drop them if we can. This requires help upstream to resolve the SIGABRT in [batch]<xsimd::batch<unsigned char>> on 32-bit ARM systems that claim neon support (i.e. on armv8l, which is Aarch64 hardware but used by debian to provide armhf environments). This is upstream issue #1260.