commit d81a8117a1b31d784f7b98135427863629d7eeca
Author: Ryan Scott <ryan.gl.scott@gmail.com>
Date:   Fri Mar 15 18:12:23 2019 -0400

    Adapt to base-4.13.0.0

diff --git a/Network/Socks5/Parse.hs b/Network/Socks5/Parse.hs
index d857274..fe4fd27 100644
--- a/Network/Socks5/Parse.hs
+++ b/Network/Socks5/Parse.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Rank2Types #-}
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE OverloadedStrings #-}
@@ -36,6 +37,7 @@ module Network.Socks5.Parse
 
 import Control.Applicative
 import Control.Monad
+import qualified Control.Monad.Fail as Fail
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as B
 import qualified Data.ByteString.Internal as B (toForeignPtr)
@@ -71,10 +73,14 @@ newtype Parser a = Parser
     { runParser :: forall r . ByteString -> Failure r -> Success a r -> Result r }
 
 instance Monad Parser where
-    fail errorMsg = Parser $ \buf err _ -> err buf ("failed: " ++ errorMsg)
+#if !(MIN_VERSION_base(4,13,0))
+    fail = Fail.fail
+#endif
     return v = Parser $ \buf _ ok -> ok buf v
     m >>= k = Parser $ \buf err ok ->
          runParser m buf err (\buf' a -> runParser (k a) buf' err ok)
+instance Fail.MonadFail Parser where
+    fail errorMsg = Parser $ \buf err _ -> err buf ("failed: " ++ errorMsg)
 instance MonadPlus Parser where
     mzero = fail "Parser.MonadPlus.mzero"
     mplus f g = Parser $ \buf err ok ->