scripts/generate-bootstraps.sh: make architecture-independent (arch "…

…all") package list optional

It is not available in some repository types, e.g. in built with "aptly".

scripts/generate-bootstraps.sh

@@ -35,18 +35,23 @@ for cmd in ar awk curl grep gzip find sed tar xargs xz zip; do
 done
 
 # Download package lists from remote repository.
-# Actually, there 2 lists are downloaded: one architecture-independent and one
-# for architecture specified as '$1' argument.
+# Actually, there 2 lists can be downloaded: one architecture-independent and
+# one for architecture specified as '$1' argument. That depends on repository.
+# If repository has been created using "aptly", then architecture-independent
+# list is not available.
 read_package_list() {
  local architecture
  for architecture in all "$1"; do
  if [ ! -e "${BOOTSTRAP_TMPDIR}/packages.${architecture}" ]; then
  echo "[*] Downloading package list for architecture '${architecture}'..."
- curl \
- --fail \
- --location \
+ if ! curl --fail --location \
  --output "${BOOTSTRAP_TMPDIR}/packages.${architecture}" \
- "${REPO_BASE_URL}/dists/stable/main/binary-${architecture}/Packages"
+ "${REPO_BASE_URL}/dists/stable/main/binary-${architecture}/Packages"; then
+ if [ "$architecture" = "all" ]; then
+ echo "[!] Skipping architecture-independent package list as not available..."
+ continue
+ fi
+ fi
  echo >> "${BOOTSTRAP_TMPDIR}/packages.${architecture}"
  fi