Error after editing makepkg.conf

Question

As the topic, I have edited my makepkg.conf in order to build via abs according to my cpu. When I try to run makpkg -csi on a pkgbuild i get this error:
==> ERROR: openbox is not available for the '' architecture.
Note that many packages may need a line added to their PKGBUILD
such as arch=('').
(there is nothing wrong with the pkgbuid in question).
My modified makepkg.conf looks like this:
# /etc/makepkg.conf
# SOURCE ACQUISITION
#-- The download utilities that makepkg should use to acquire sources
# Format: 'protocol::agent'
DLAGENTS=('ftp::/usr/bin/wget -c --passive-ftp -t 3 --waitretry=3'
'http::/usr/bin/wget -c -t 3 --waitretry=3'
'https::/usr/bin/wget -c -t 3 --waitretry=3 --no-check-certificate'
'rsync::/usr/bin/rsync -z'
'scp::/usr/bin/scp -C')
# Other common tools:
# /usr/bin/snarf
# /usr/bin/lftpget -c
# /usr/bin/curl
# ARCHITECTURE, COMPILE FLAGS
CHOST="x86_64-pc-linux-gnu"
CFLAGS="-march=athlon64 -O2 -pipe"
CXXFLAGS="${CFLAGS}"
MAKEFLAGS="-j3"
#-- Exclusive: will only run on -march=x86-64
# -march (or -mcpu) builds exclusively for an architecture
# -mtune optimizes for an architecture, but builds for whole processor family
#-- Make Flags: change this for DistCC/SMP systems
#MAKEFLAGS="-j2"
# BUILD ENVIRONMENT
# Defaults: BUILDENV=(fakeroot !distcc color !ccache !xdelta)
# A negated environment option will do the opposite of the comments below.
#-- fakeroot: Allow building packages as a non-root user
#-- distcc: Use the Distributed C/C++/ObjC compiler
#-- color: Colorize output messages
#-- ccache: Use ccache to cache compilation
#-- xdelta: Generate delta patch from previous to current package
BUILDENV=(fakeroot !distcc color !ccache !xdelta)
#-- If using DistCC, your MAKEFLAGS will also need modification. In addition,
#-- specify a space-delimited list of hosts running in the DistCC cluster.
#DISTCC_HOSTS=""
# GLOBAL PACKAGE OPTIONS
# These are default values for the options=() settings
# Default: OPTIONS=(strip !docs libtool emptydirs)
# A negated option will do the opposite of the comments below.
#-- strip: Strip symbols from binaries/libraries
#-- docs: Save doc and info directories
#-- libtool: Leave libtool (.la) files in packages
#-- emptydirs: Leave empty directories in packages
OPTIONS=(strip !docs libtool emptydirs)
#-- File integrity checks to use. Valid: md5, sha1, sha256, sha384, sha512
INTEGRITY_CHECK=(md5)
#-- Info and doc directories to remove (if option set correctly above)
DOC_DIRS=(usr/{,share/}{info,doc,gtk-doc} opt/*/{info,doc,gtk-doc})
# PACKAGE OUTPUT
# Default: put built package and cached source in build directory
#-- Destination: specify a fixed directory where all packages will be placed
#PKGDEST=/home/packages
#-- Source cache: specify a fixed directory where source files will be cached
#SRCDEST=/home/sources
#-- Source root: specify location where PKGBUILDs are located for '--builddeps'
#SRCROOT=/home/pkgbuilds
#-- Packager: name/email of the person or organization building packages
#PACKAGER="John Doe <[email protected]>"
# BUILDSCRIPT/EXTENSION DEFAULTS
# WARNING: Do NOT modify these variables unless you know what you are
# doing.
BUILDSCRIPT='PKGBUILD'
PKGEXT='.pkg.tar.gz'
SRCEXT='.src.tar.gz'
DB_COMPRESSION='gz'
DB_CHECKSUMS=(md5)
# vim: set ft=sh ts=2 sw=2 et:
ps. I have an amd athlon 64 x2.

Answer 1

You are missing the CARCH- field(?). Add
CARCH="x86_64"
into your makepkg.conf (it's above CHOST by default).