1 files changed, 8 insertions, 6 deletions
diff --git a/pkgs/build-support/buildenv/default.nix b/pkgs/build-support/buildenv/default.nix
index 8cbf0dc6c8e4..e7ac87c109f3 100644
--- a/pkgs/build-support/buildenv/default.nix
+++ b/pkgs/build-support/buildenv/default.nix
@@ -34,12 +34,14 @@
 }:
 
 runCommand name
-  { inherit manifest ignoreCollisions passthru pathsToLink extraPrefix postBuild buildInputs;
-    pkgs = builtins.toJSON (map (drv: {
-      paths = [ drv ]; # FIXME: handle multiple outputs
-      priority = drv.meta.priority or 5;
-    }) paths);
-    preferLocalBuild = true;
+  rec { inherit manifest ignoreCollisions passthru pathsToLink extraPrefix postBuild buildInputs;
+        pkgs = builtins.toJSON (map (drv: {
+          paths = [ drv ]; # FIXME: handle multiple outputs
+          priority = drv.meta.priority or 5;
+        }) paths);
+        preferLocalBuild = true;
+        # XXX: The size is somewhat arbitrary
+        passAsFile = if builtins.stringLength pkgs >= 128*1024 then [ "pkgs" ] else null;
   }
   ''
     ${perl}/bin/perl -w ${./builder.pl}