Currently, by default, binaries in /usr/local/bin are not included in PATH and libraries in /usr/local/lib are not included in the shared library cache. However, the /usr/local hierarchy *is* included by default, in the filesystem package, along with the scripts that would make /usr/local/{bin,lib} usable: /etc/profile and /etc/ld.so.conf{,.d}. This is asymmetric, and annoying to people who compile their own software. Additionally, not supporting /usr/local/{bin,lib} by default apparently places Arch in the minority: Fedora Core, Ubuntu, FreeBSD, and OpenBSD all support it. I'm not advocating a keeping-up-with-the-Joneses kind of thing, but rather principle of least surprise for users of other operating systems.

I've attached a proposed patch.