move preBuildHook defaulting to globals.cc

src/libstore/build.cc

@@ -59,12 +59,10 @@
 /* chroot-like behavior from Apple's sandbox */
 #if __APPLE__
     #define SANDBOX_ENABLED 1
-    #define DARWIN_PREBUILD 1
     #define DEFAULT_ALLOWED_IMPURE_PREFIXES "/System/Library /usr/lib /dev /bin/sh"
 #else
     #define SANDBOX_ENABLED 0
     #define DEFAULT_ALLOWED_IMPURE_PREFIXES "/bin" "/usr/bin"
-    #define DARWIN_PREBUILD 0
 #endif
 
 #if CHROOT_ENABLED
@@ -2047,11 +2045,6 @@ void DerivationGoal::startBuilder()
                 }
     }
 
-#if DARWIN_PREBUILD
-    if (settings.preBuildHook == "")
-      settings.preBuildHook = settings.nixLibexecDir + "/nix/resolve-system-dependencies.pl";
-#endif
-
     if (settings.preBuildHook != "") {
         printMsg(lvlChatty, format("executing pre-build hook ‘%1%’")
             % settings.preBuildHook);

src/libstore/globals.cc

@@ -77,6 +77,11 @@ void Settings::processEnvironment()
     nixLibexecDir = canonPath(getEnv("NIX_LIBEXEC_DIR", NIX_LIBEXEC_DIR));
     nixBinDir = canonPath(getEnv("NIX_BIN_DIR", NIX_BIN_DIR));
     nixDaemonSocketFile = canonPath(nixStateDir + DEFAULT_SOCKET_PATH);
+
+    // should be set with the other config options, but depends on nixLibexecDir
+#ifdef __APPLE__
+    preBuildHook = nixLibexecDir + "/nix/resolve-system-dependencies.pl";
+#endif
 }