archbuild.in: set pacman cache dir to /var/cache/archbuild32 in case …

…of non-x86_64-build, so we do not use any-packages from x86_64 mirrors, and cross-mount inside to /var/cache/pacman/pkg

archbuild.in

@@ -47,6 +47,14 @@ done
 
 check_root SOURCE_DATE_EPOCH
 
+if [ "${arch}" = "x86_64" ]; then
+	cache_dir=''
+else
+	mkdir -p '/var/cache/archbuild32'
+	cache_dir='-c/var/cache/archbuild32'
+	makechrootpkg_args+=('-d/var/cache/archbuild32:/var/cache/pacman/pkg')
+fi
+
 # Pass all arguments after -- right to makepkg
 makechrootpkg_args+=("${@:$OPTIND}")
 
@@ -69,13 +77,15 @@ if ${clean_first} || [[ ! -d "${chroots}/${repo}-${arch}" ]]; then
 	setarch "${arch}" mkarchroot \
 		-C "@pkgdatadir@/pacman-${repo}${arch_ext}.conf" \
 		-M "@pkgdatadir@/makepkg-${arch}.conf" \
+		${cache_dir} \
 		"${chroots}/${repo}-${arch}/root" \
 		"${base_packages[@]}" || abort
 else
 	lock 9 "${chroots}/${repo}-${arch}/root.lock" "Locking clean chroot"
 	arch-nspawn \
 		-C "@pkgdatadir@/pacman-${repo}${arch_ext}.conf" \
 		-M "@pkgdatadir@/makepkg-${arch}.conf" \
+		${cache_dir} \
 		"${chroots}/${repo}-${arch}/root" \
                 pacman -Syu --noconfirm || abort
 fi