From 9172c1eee2e376ef9070d1db0586471c52397242 Mon Sep 17 00:00:00 2001
From: Matthew Bauer <mjbauer95@gmail.com>
Date: Wed, 31 Oct 2018 14:26:54 -0500
Subject: [PATCH] setup.sh: avoid running the same hook twice
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In strictDeps=false, we don’t want the same package hook to be run
twice, otherwise we get duplicates in some flags.

Fixes #41340
---
 pkgs/stdenv/generic/setup.sh | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/pkgs/stdenv/generic/setup.sh b/pkgs/stdenv/generic/setup.sh
index 8af369b1d17d..7e55f0db2aac 100644
--- a/pkgs/stdenv/generic/setup.sh
+++ b/pkgs/stdenv/generic/setup.sh
@@ -562,6 +562,10 @@ _addToEnv() {
             (( "$depHostOffset" <= "$depTargetOffset" )) || continue
             local hookRef="${hookVar}[$depTargetOffset - $depHostOffset]"
             if [[ -z "${strictDeps-}" ]]; then
+
+                # Keep track of which packages we have visited before.
+                local visitedPkgs=""
+
                 # Apply environment hooks to all packages during native
                 # compilation to ease the transition.
                 #
@@ -574,7 +578,11 @@ _addToEnv() {
                     ${pkgsHostTarget+"${pkgsHostTarget[@]}"} \
                     ${pkgsTargetTarget+"${pkgsTargetTarget[@]}"}
                 do
+                    if [[ "$visitedPkgs" = *"$pkg"* ]]; then
+                        continue
+                    fi
                     runHook "${!hookRef}" "$pkg"
+                    visitedPkgs+=" $pkg"
                 done
             else
                 local pkgsRef="${pkgsVar}[$depTargetOffset - $depHostOffset]"