core: do not abort on a failed apt update

core/core.func

@@ -1418,7 +1418,7 @@ ensure_tput() {
     if grep -qi 'alpine' /etc/os-release; then
       apk add --no-cache ncurses >/dev/null 2>&1
     elif command -v apt-get >/dev/null 2>&1; then
-      apt-get update -qq >/dev/null
+      apt-get update -qq >/dev/null 2>&1 || true
       apt-get install -y -qq ncurses-bin >/dev/null 2>&1
     fi
   fi
@@ -2372,32 +2372,36 @@ function get_lxc_ip() {
 # apt_update_safe()
 #
 # - Runs apt-get update without letting a partial failure abort the caller
-# - Disarms errexit and the ERR trap for the duration, then restores them
-# - Warns on a non-zero exit and hints at the enterprise-repo 401/403 case
+# - Retries up to three times; a mirror hiccup is the usual cause
+# - Leaves the caller's shell options and ERR trap untouched
+# - Warns after the last attempt and hints at the enterprise-repo 401/403 case
 # ------------------------------------------------------------------------------
 apt_update_safe() {
-  local logfile
+  local logfile rc=0 attempt from
   logfile="$(get_active_logfile)"
 
-  local _restore_errexit=false
-  [[ "$-" == *e* ]] && _restore_errexit=true
-
-  set +Eeuo pipefail
-  trap - ERR
-
-  apt-get update >>"$logfile" 2>&1
-  local rc=$?
-
-  if $_restore_errexit; then
-    set -Eeuo pipefail
-    trap 'error_handler' ERR
-  fi
+  # `|| rc=$?` is exempt from errexit and the ERR trap, so nothing here has to
+  # touch the caller's shell options.
+  for attempt in 1 2 3; do
+    from=$(($(wc -l <"$logfile" 2>/dev/null || echo 0) + 1))
+    rc=0
+    apt-get update >>"$logfile" 2>&1 || rc=$?
+    if [[ "${VERBOSE:-no}" == "yes" ]]; then
+      tail -n "+${from}" "$logfile" 2>/dev/null
+    fi
+    if ((rc == 0)); then
+      return 0
+    fi
+    if ((attempt < 3)); then
+      sleep $((attempt * 5))
+    fi
+  done
 
   if [[ $rc -ne 0 ]]; then
-    msg_warn "apt-get update exited with code ${rc} — some repositories may have failed."
+    msg_warn "apt-get update exited with code ${rc} after 3 attempts — some repositories may have failed."
 
     # Check log for common 401/403 enterprise repo issues
-    if grep -qiE '401\s*Unauthorized|403\s*Forbidden|enterprise\.proxmox\.com' "$logfile" 2>/dev/null; then
+    if tail -n "+${from}" "$logfile" 2>/dev/null | grep -qiE '401\s*Unauthorized|403\s*Forbidden|enterprise\.proxmox\.com'; then
       echo -e "${TAB}${INFO} ${YWB}Hint: Proxmox enterprise repository returned an auth error.${CL}"
       echo -e "${TAB}       If you don't have a subscription, you can disable the enterprise"
       echo -e "${TAB}       repo and use the no-subscription repo instead."

incus/tools.func

@@ -196,7 +196,7 @@ network_check() {
 
 update_os() {
   msg_info "Updating Container OS"
-  $STD apt update
+  apt_update_safe
   $STD apt upgrade -y
   msg_ok "Updated Container OS"
 }
@@ -260,7 +260,7 @@ _bootstrap() {
 
     if [[ "$need_bootstrap" -eq 1 ]]; then
       msg_info "Installing Base Dependencies"
-      $STD apt update
+      apt_update_safe
       $STD apt install -y "${base_pkgs[@]}"
       msg_ok "Installed Base Dependencies"
     fi

lib/db.func

@@ -1052,7 +1052,7 @@ EOF
     if ! install_packages_with_retry "mysql-community-server" "mysql-community-client"; then
       msg_warn "MySQL 8.4 LTS installation failed – falling back to MariaDB"
       cleanup_old_repo_files "mysql"
-      $STD apt update
+      apt_update_safe
       install_packages_with_retry "mariadb-server" "mariadb-client" || {
         msg_error "Failed to install database engine (MySQL/MariaDB fallback)"
         return 100

lib/runtime.func

@@ -1282,7 +1282,7 @@ setup_nodejs() {
 
   # Ensure jq is available for JSON parsing
   if ! command -v jq &>/dev/null; then
-    $STD apt update
+    apt_update_safe
     $STD apt install -y jq || {
       msg_error "Failed to install jq"
       return 100

lib/system.func

@@ -2481,6 +2481,6 @@ Suites: trixie-security
 Components: main contrib non-free non-free-firmware
 EOF
   fi
-  $STD apt update
+  apt_update_safe
   return 0
 }