fixed

download.sh

@@ -33,19 +33,29 @@ WORKDIR=$(mktemp -d "$TMPDIR/${SCRIPT_NAME%.sh}.XXXXXX")
 cleanup_tmp() { rm -rf "$WORKDIR" 2>/dev/null || true; }
 
 # ----------------------------- lock/unlock logic ------------------------------
+# Use a fixed numeric FD (200) for wider Bash compatibility (e.g., macOS bash 3.2).
 LOCK_FD=200
 LOCK_FILE="/tmp/${SCRIPT_NAME}.lock"
+LOCK_HELD=0
+
 lock() {
   log "Creating lock… ($LOCK_FILE)"
-  # shellcheck disable=SC2094
-  exec {LOCK_FD}>"$LOCK_FILE" || die "Could not open lock file $LOCK_FILE"
-  if ! flock -n "$LOCK_FD"; then
+  exec ${LOCK_FD}>"$LOCK_FILE" || die "Could not open lock file $LOCK_FILE"
+  if flock -n ${LOCK_FD}; then
+    LOCK_HELD=1
+  else
     die "Lock failed — another process is running."
   fi
 }
+
 unlock() {
+  if (( LOCK_HELD )); then
     log "Releasing lock…"
-  flock -u "$LOCK_FD" || true
+    flock -u ${LOCK_FD} || true
+    # Close the FD to avoid lingering descriptors
+    exec ${LOCK_FD}>&- || true
+    LOCK_HELD=0
+  fi
 }
 
 # Always cleanup on exit/interrupt