from Documentation/RelNotes-1.5.6.txt: * cpio is no longer used; neither "curl" binary (libcurl is still used). and grepping the 1.6.5.1 source shows only one hit on `cpio` -- git-gui. so cpio should only be required when git-gui is installed. not that i can tell when that actually gets installed as none of my systems have it ... is it OS X only or something ?
cpio is needed to build git-gui still, but nothing else. Latest ~arch ebuild updated suitably.