def METHOD_NAME(arch):
    deb_arch = _DEB_ARCH[arch]
    command = [
        "dpkg-buildpackage",
        # TODO: Use long options once we stop supporting Debian Jesse. They're more
        # explicit.
        #
        # Long options were added in dpkg 1.18.8 which is part of Debian Stretch.
        #
        # https://git.dpkg.org/cgit/dpkg/dpkg.git/commit/?h=1.18.x&id=293bd243a19149165fc4fd8830b16a51d471a5e9
        # https://packages.debian.org/stretch/dpkg-dev
        "-us",  # --unsigned-source
        "-uc",  # --unsigned-changes
        "-b",  # --build=binary
        f"--host-arch={deb_arch}",
    ]
    if _is_chroot_available(arch):
        flattened_command = " ".join(command)
        command = [
            "chroot",
            f"/srv/{_DEB_DIST}-{deb_arch}",
            "bash",
            "-c",
            f"cd /tmp/*/source; {flattened_command}",
        ]
    return command