From 5c06a8d3283139140e765b5f10ad7102a6a3e964 Mon Sep 17 00:00:00 2001
From: Matthew Bauer <mjbauer95@gmail.com>
Date: Fri, 23 Aug 2019 20:24:39 -0400
Subject: [PATCH] Reset tmpDirInSandbox for unsandboxed

---
 src/libstore/build.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 0f71e7511..96e9b8edd 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -2330,6 +2330,7 @@ void DerivationGoal::startBuilder()
         int res = helper.wait();
         if (res != 0 && settings.sandboxFallback) {
             useChroot = false;
+            tmpDirInSandbox = tmpDir;
             goto fallback;
         } else if (res != 0)
             throw Error("unable to start build process");