fix: read snapshot of tracked file and close it afterwards

We were writing to the file as the file was opened in read mode. This
lead to PRs not being removed after first time notified.

nixpkgs_notifier.py

@@ -232,21 +232,46 @@ def main():
                     if pr:
                         print("  " + str(pr) + "  " + getPRTitle(pr))
     
-    elif sys.argv[1] == "listen":
+elif sys.argv[1] == "listen":
-        while True:
+    while True:
+        try:
             if trackedPRFile.exists():
+                # Read a snapshot of the file first so we don't modify
+                # tracked.txt while iterating over it.
                 with trackedPRFile.open("r") as f:
+                    tracked_prs = []
                     for line in f:
-                        PR = int(line.strip())
+                        line = line.strip()
-                        if fetchStatus(PR) == "accepted":
+                        if not line:
+                            continue
+                        tracked_prs.append(int(line))
+                
+                for PR in tracked_prs:
+                    try:
+                        status = fetchStatus(PR)
+
+                        if status == "accepted":
+                            print(f"PR #{PR} accepted")
+
                             if shouldLocalNotify:
                                 localNotify(PR)
                             if shouldMatrixNotify:
                                 matrixNotify(PR)
                             removeTracker(PR)
-                        sleep(configFetchTime) # avoids to send request to quickly to the website
+                            print(f"Removed PR #{PR} from tracking")
-            sleep(configTime)
+
-    
+                    except Exception as e:
+                        print(
+                            f"Failed to process PR #{PR}: {e}"
+                        )
+
+                    # Avoid hammering the tracker website
+                    sleep(configFetchTime)
+
+        except Exception as e:
+            print(f"Listener loop error: {e}")
+
+        sleep(configTime)
     else:
         print("Unknown argument \"" + sys.argv[1] + "\"\nAccepted arguments are:\n    add\n    remove or rm\n    list or ls\n    listen")