buildInLinuxVM: Workaround bug #16742

This is blocking the channel update: #16949

pkgs/build-support/vm/default.nix

···
     origArgs = args;
     origBuilder = builder;
     QEMU_OPTS = "${QEMU_OPTS} -m ${toString memSize}";
+    passAsFile = []; # HACK fix - see https://github.com/NixOS/nixpkgs/issues/16742
   });