diff -ru EdisonAPI-1.3.1.orig/src/Data/Edison/Seq/ListSeq.hs EdisonAPI-1.3.1/src/Data/Edison/Seq/ListSeq.hs
--- EdisonAPI-1.3.1.orig/src/Data/Edison/Seq/ListSeq.hs	2016-06-03 00:49:51.000000000 -0400
+++ EdisonAPI-1.3.1/src/Data/Edison/Seq/ListSeq.hs	2019-04-19 13:54:07.461113622 -0400
@@ -131,25 +131,25 @@
 rcons x s = s ++ [x]
 append = (++)
 
-lview [] = fail "ListSeq.lview: empty sequence"
+lview [] = error "ListSeq.lview: empty sequence"
 lview (x:xs) = return (x, xs)
 
-lheadM [] = fail "ListSeq.lheadM: empty sequence"
+lheadM [] = error "ListSeq.lheadM: empty sequence"
 lheadM (x:xs) = return x
 
 lhead [] = error "ListSeq.lhead: empty sequence"
 lhead (x:xs) = x
 
-ltailM [] = fail "ListSeq.ltailM: empty sequence"
+ltailM [] = error "ListSeq.ltailM: empty sequence"
 ltailM (x:xs) = return xs
 
 ltail [] = error "ListSeq.ltail: empty sequence"
 ltail (x:xs) = xs
 
-rview [] = fail "ListSeq.rview: empty sequence"
+rview [] = error "ListSeq.rview: empty sequence"
 rview xs = return (rhead xs, rtail xs)
 
-rheadM [] = fail "ListSeq.rheadM: empty sequence"
+rheadM [] = error "ListSeq.rheadM: empty sequence"
 rheadM (x:xs) = rh x xs
   where rh y [] = return y
         rh y (x:xs) = rh x xs
@@ -159,7 +159,7 @@
   where rh y [] = y
         rh y (x:xs) = rh x xs
 
-rtailM [] = fail "ListSeq.rtailM: empty sequence"
+rtailM [] = error "ListSeq.rtailM: empty sequence"
 rtailM (x:xs) = return (rt x xs)
   where rt y [] = []
         rt y (x:xs) = y : rt x xs
@@ -255,9 +255,9 @@
 lookup i xs = ID.runIdentity (lookupM i xs)
 
 lookupM i xs
-  | i < 0 = fail "ListSeq.lookup: not found"
+  | i < 0 = error "ListSeq.lookup: not found"
   | otherwise = case drop i xs of
-                  [] -> fail "ListSeq.lookup: not found"
+                  [] -> error "ListSeq.lookup: not found"
                   (x:_) -> return x
 
 lookupWithDefault d i xs