From 07d38f3c22ab7d89299db4da24104b34572836c9 Mon Sep 17 00:00:00 2001
From: Eric Koch <koch.eric.w@gmail.com>
Date: Mon, 30 Sep 2024 10:15:13 -0400
Subject: [PATCH] Raise error with more informative message for these outliers

---
 fil_finder/length.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fil_finder/length.py b/fil_finder/length.py
index f6c729c..05d9b0c 100644
--- a/fil_finder/length.py
+++ b/fil_finder/length.py
@@ -443,6 +443,10 @@ def longest_path(edge_list, nodes, verbose=False,
             node_extrema.append((j[0], i))
             values.append(j[1])
 
+        if len(values) == 0:
+            raise ValueError("Unable to find maximum path. This is likely a bug. Please"
+                             " report to https://github.com/e-koch/FilFinder.")
+
         max_path_length = max(values)
         start, finish = node_extrema[values.index(max_path_length)]
         extremum.append([start, finish])
@@ -829,7 +833,7 @@ def get_weight(pat):
 
     return long_path, long_path_length
 
-  
+
 def merge_nodes(node, G):
     '''
     Combine a node into its neighbors.