From 4f4a14453ae8dbfc24a1e580aa695165e9d81f0a Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <eelco.dolstra@logicblox.com>
Date: Fri, 18 Oct 2013 14:51:25 +0200
Subject: [PATCH] Don't set $PS1 in non-interactive shells

Shouldn't really matter, but you never know.
---
 scripts/nix-build.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/nix-build.in b/scripts/nix-build.in
index 4bf85ae13..8ac95e90e 100755
--- a/scripts/nix-build.in
+++ b/scripts/nix-build.in
@@ -209,7 +209,7 @@ foreach my $expr (@exprs) {
             '[ -e $stdenv/setup ] && source $stdenv/setup; ' .
             ($pure ? '' : 'PATH=$PATH:$p; ') .
             'set +e; ' .
-            'PS1="\n\[\033[1;32m\][nix-shell:\w]$\[\033[0m\] "; ' .
+            '[ -n "$PS1" ] && PS1="\n\[\033[1;32m\][nix-shell:\w]$\[\033[0m\] "; ' .
             'unset NIX_ENFORCE_PURITY; ' .
             'shopt -u nullglob; ' .
             $envCommand);