Install 2nd instance of Arch Linux without internet connection

Question

I have successfully install a first instance of Arch Linux using Arch Linux ISO + pacstrap + pacman with internet connection.
I have updated to latest package database list (/var/lib/pacman/sync) and package cache files (/var/cache/pacman/pkg) in first instance of Arch Linux with "pacman -Swyu".
Next, I would like to install 2nd instance of Arch Linux without using internet connection.
I share the "/var/lib/pacman/sync" and "/var/cache/pacman/pkg" via NFS from first Arch Linux instance.
I boot the 2nd instance with Arch Linux ISO and attempt to install without internet connection.  I mount the two NFS shares from 1st instance to "/var/cache/pacman/pkg" and "/mnt/var/lib/pacman/sync" respectively.  I execute
   # pacstrap -i -c /mnt"
to start installation.
I found it is almost impossible with current implementation of pacstrap script.  The pacstrap script always attempt to update package database list with -Sy option.
I think some amendments on pacstrap script is needed to install Arch Linux without internet connection.

Answer 1

I made the edit by adding the option -o to do what you want.
I am too lazy for a feature request right now...
#!/bin/bash
# Assumptions:
# 1) User has partitioned, formatted, and mounted partitions on /mnt
# 2) Network is functional
# 3) Arguments passed to the script are valid pacman targets
# 4) A valid mirror appears in /etc/pacman.d/mirrorlist
shopt -s extglob
out() { printf "$1 $2\n" "${@:3}"; }
error() { out "==> ERROR:" "$@"; } >&2
msg() { out "==>" "$@"; }
msg2() { out " ->" "$@";}
die() { error "$@"; exit 1; }
in_array() {
local i
for i in "${@:2}"; do
[[ $1 = "$i" ]] && return
done
track_mount() {
mount "$@" && CHROOT_ACTIVE_MOUNTS=("$2" "${CHROOT_ACTIVE_MOUNTS[@]}")
api_fs_mount() {
CHROOT_ACTIVE_MOUNTS=()
{ mountpoint -q "$1" || track_mount "$1" "$1" --bind; } &&
track_mount proc "$1/proc" -t proc -o nosuid,noexec,nodev &&
track_mount sys "$1/sys" -t sysfs -o nosuid,noexec,nodev &&
track_mount udev "$1/dev" -t devtmpfs -o mode=0755,nosuid &&
track_mount devpts "$1/dev/pts" -t devpts -o mode=0620,gid=5,nosuid,noexec &&
track_mount shm "$1/dev/shm" -t tmpfs -o mode=1777,nosuid,nodev &&
track_mount run "$1/run" -t tmpfs -o nosuid,nodev,mode=0755 &&
track_mount tmp "$1/tmp" -t tmpfs -o mode=1777,strictatime,nodev,nosuid
api_fs_umount() {
umount "${CHROOT_ACTIVE_MOUNTS[@]}"
valid_number_of_base() {
local base=$1 len=${#2} i=
for (( i = 0; i < len; i++ )); do
(( (${2:i:1} & ~(base - 1)) == 0 )) || return
done
mangle() {
local i= chr= out=
unset {a..f} {A..F}
for (( i = 0; i < ${#1}; i++ )); do
chr=${1:i:1}
case $chr in
[[:space:]\\])
printf -v chr '%03o' "'$chr"
out+=\\
# fallthrough
out+=$chr
esac
done
printf '%s' "$out"
unmangle() {
local i= chr= out= len=$(( ${#1} - 4 ))
unset {a..f} {A..F}
for (( i = 0; i < len; i++ )); do
chr=${1:i:1}
case $chr in
if valid_number_of_base 8 "${1:i+1:3}" ||
valid_number_of_base 16 "${1:i+1:3}"; then
printf -v chr '%b' "${1:i:4}"
(( i += 3 ))
fi
# fallthrough
out+=$chr
esac
done
printf '%s' "$out${1:i}"
dm_name_for_devnode() {
read dm_name <"/sys/class/block/${1#/dev/}/dm/name"
if [[ $dm_name ]]; then
printf '/dev/mapper/%s' "$dm_name"
else
# don't leave the caller hanging, just print the original name
# along with the failure.
print '%s' "$1"
error 'Failed to resolve device mapper name for: %s' "$1"
fi
fstype_is_pseudofs() {
# list taken from util-linux source: libmount/src/utils.c
local -A pseudofs_types=([anon_inodefs]=1
[autofs]=1
[bdev]=1
[binfmt_misc]=1
[cgroup]=1
[configfs]=1
[cpuset]=1
[debugfs]=1
[devfs]=1
[devpts]=1
[devtmpfs]=1
[dlmfs]=1
[fuse.gvfs-fuse-daemon]=1
[fusectl]=1
[hugetlbfs]=1
[mqueue]=1
[nfsd]=1
[none]=1
[pipefs]=1
[proc]=1
[pstore]=1
[ramfs]=1
[rootfs]=1
[rpc_pipefs]=1
[securityfs]=1
[sockfs]=1
[spufs]=1
[sysfs]=1
[tmpfs]=1)
(( pseudofs_types["$1"] ))
newroot=/mnt
hostcache=0
copykeyring=1
copymirrorlist=1
offline=0
usage() {
cat <<EOF
usage: ${0##*/} [options] root [packages...]
Options:
-C config Use an alternate config file for pacman
-c Use the package cache on the host, rather than the target
-d Allow installation to a non-mountpoint directory
-G Avoid copying the host's pacman keyring to the target
-i Avoid auto-confirmation of package selections
-M Avoid copying the host's mirrorlist to the target
-o Do not update the pacman cache for offline installation
-h Print this help message
pacstrap installs packages to the specified new root directory. If no packages
are given, pacstrap defaults to the "base" group.
EOF
if [[ -z $1 || $1 = @(-h|--help) ]]; then
usage
exit $(( $# ? 0 : 1 ))
fi
(( EUID == 0 )) || die 'This script must be run with root privileges'
while getopts ':C:cdGiMo' flag; do
case $flag in
C)
pacman_config=$OPTARG
d)
directory=1
c)
hostcache=1
i)
interactive=1
G)
copykeyring=0
M)
copymirrorlist=0
o)
offline=1
die '%s: option requires an argument -- '\''%s'\' "${0##*/}" "$OPTARG"
die '%s: invalid option -- '\''%s'\' "${0##*/}" "$OPTARG"
esac
done
shift $(( OPTIND - 1 ))
(( $# )) || die "No root directory specified"
newroot=$1; shift
pacman_args=("${@:-base}")
if (( ! hostcache )); then
pacman_args+=(--cachedir="$newroot/var/cache/pacman/pkg")
fi
if (( ! interactive )); then
pacman_args+=(--noconfirm)
fi
if (( ! offline )); then
pacman_args+=(-y)
fi
if [[ $pacman_config ]]; then
pacman_args+=(--config="$pacman_config")
fi
[[ -d $newroot ]] || die "%s is not a directory" "$newroot"
if ! mountpoint -q "$newroot" && (( ! directory )); then
die '%s is not a mountpoint!' "$newroot"
fi
# create obligatory directories
msg 'Creating install root at %s' "$newroot"
mkdir -m 0755 -p "$newroot"/var/{cache/pacman/pkg,lib/pacman,log} "$newroot"/{dev,run,etc}
mkdir -m 1777 -p "$newroot"/tmp
mkdir -m 0555 -p "$newroot"/{sys,proc}
# always call umount on quit after this point
trap 'api_fs_umount "$newroot" 2>/dev/null' EXIT
# mount API filesystems
api_fs_mount "$newroot" || die "failed to setup API filesystems in new root"
msg 'Installing packages to %s' "$newroot"
if ! pacman -r "$newroot" -S "${pacman_args[@]}"; then
die 'Failed to install packages to new root'
fi
if (( copykeyring )); then
# if there's a keyring on the host, copy it into the new root, unless it exists already
if [[ -d /etc/pacman.d/gnupg && ! -d $newroot/etc/pacman.d/gnupg ]]; then
cp -a /etc/pacman.d/gnupg "$newroot/etc/pacman.d/"
fi
fi
if (( copymirrorlist )); then
# install the host's mirrorlist onto the new root
cp -a /etc/pacman.d/mirrorlist "$newroot/etc/pacman.d/"
fi
# vim: et ts=2 sw=2 ft=sh: