From 2d0fb071256c1157493c42048402945cbac18484 Mon Sep 17 00:00:00 2001
From: Bodigrim <andrew.lelechenko@gmail.com>
Date: Sun, 8 Jun 2025 19:10:55 +0200
Subject: [PATCH] Deduplicate pure args

---
 Cabal/src/Distribution/Simple/PreProcess.hs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Cabal/src/Distribution/Simple/PreProcess.hs b/Cabal/src/Distribution/Simple/PreProcess.hs
index 2484bcf8ac2..03088b3cd8e 100644
--- a/Cabal/src/Distribution/Simple/PreProcess.hs
+++ b/Cabal/src/Distribution/Simple/PreProcess.hs
@@ -512,7 +512,7 @@ ppHsc2hs bi lbi clbi =
     -- Returns a list of command line arguments that can either be passed
     -- directly, or via a response file.
     genPureArgs :: Version -> ConfiguredProgram -> String -> String -> [String]
-    genPureArgs hsc2hsVersion gccProg inFile outFile =
+    genPureArgs hsc2hsVersion gccProg inFile outFile = ordNub $
       -- Additional gcc options
       [ "--cflag=" ++ opt
       | opt <-