From ba75c69e0014178cf524cc07427bb4e9eac333f7 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Mon, 15 Jan 2018 12:14:43 +0100
Subject: [PATCH] Barf when using a diverted store on macOS

Fixes #1792.
---
 src/libstore/build.cc | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index d4bd650ba..523d737d9 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -1810,8 +1810,13 @@ void DerivationGoal::startBuilder()
             useChroot = !fixedOutput && get(drv->env, "__noChroot") != "1";
     }
 
-    if (worker.store.storeDir != worker.store.realStoreDir)
-        useChroot = true;
+    if (worker.store.storeDir != worker.store.realStoreDir) {
+        #if __linux__
+            useChroot = true;
+        #else
+            throw Error("building using a diverted store is not supported on this platform");
+        #endif
+    }
 
     /* If `build-users-group' is not empty, then we have to build as
        one of the members of that group. */