diff --git a/.gitignore b/.gitignore
index e69de29..b2be92b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1 @@
+result
diff --git a/flake.lock b/flake.lock
index ade82ac..8512316 100644
--- a/flake.lock
+++ b/flake.lock
@@ -175,11 +175,11 @@
     },
     "flake-utils_4": {
       "locked": {
-        "lastModified": 1676283394,
-        "narHash": "sha256-XX2f9c3iySLCw54rJ/CZs+ZK6IQy7GXNY4nSOyu2QG4=",
+        "lastModified": 1678901627,
+        "narHash": "sha256-U02riOqrKKzwjsxc/400XnElV+UtPUQWpANPlyazjH0=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "3db36a8b464d0c4532ba1c7dda728f4576d6d073",
+        "rev": "93a2b84fc4b70d9e089d029deacc3583435c2ed6",
         "type": "github"
       },
       "original": {
@@ -330,11 +330,11 @@
         "rust-overlay": "rust-overlay_2"
       },
       "locked": {
-        "lastModified": 1679587834,
-        "narHash": "sha256-x55B7l1Sp/oMrPecwZFcDiqYh1uL+h19nkw274mgKys=",
+        "lastModified": 1679605987,
+        "narHash": "sha256-EWkCsAQiC7B3v9FqNmtxYARX3EDAA1hD8b+9s19cuCs=",
         "owner": "tweag",
         "repo": "nickel",
-        "rev": "7284ce50a312c0a96b188e4c81e6e258b9521075",
+        "rev": "985d19c12387f2175f902b449fc9503c4ee4d5be",
         "type": "github"
       },
       "original": {
@@ -412,11 +412,11 @@
     },
     "nixpkgs-stable": {
       "locked": {
-        "lastModified": 1673800717,
-        "narHash": "sha256-SFHraUqLSu5cC6IxTprex/nTsI81ZQAtDvlBvGDWfnA=",
+        "lastModified": 1678872516,
+        "narHash": "sha256-/E1YwtMtFAu2KUQKV/1+KFuReYPANM2Rzehk84VxVoc=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "2f9fd351ec37f5d479556cd48be4ca340da59b8f",
+        "rev": "9b8e5abb18324c7fe9f07cb100c3cd4a29cda8b8",
         "type": "github"
       },
       "original": {
@@ -428,11 +428,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1678470307,
-        "narHash": "sha256-OEeMUr3ueLIXyW/OaFUX5jUdimyQwMg/7e+/Q0gC/QE=",
+        "lastModified": 1678898370,
+        "narHash": "sha256-xTICr1j+uat5hk9FyuPOFGxpWHdJRibwZC+ATi0RbtE=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "0c4800d579af4ed98ecc47d464a5e7b0870c4b1f",
+        "rev": "ac718d02867a84b42522a0ece52d841188208f2c",
         "type": "github"
       },
       "original": {
@@ -502,11 +502,11 @@
         "nixpkgs-stable": "nixpkgs-stable"
       },
       "locked": {
-        "lastModified": 1678376203,
-        "narHash": "sha256-3tyYGyC8h7fBwncLZy5nCUjTJPrHbmNwp47LlNLOHSM=",
+        "lastModified": 1678976941,
+        "narHash": "sha256-skNr08frCwN9NO+7I77MjOHHAw+L410/37JknNld+W4=",
         "owner": "cachix",
         "repo": "pre-commit-hooks.nix",
-        "rev": "1a20b9708962096ec2481eeb2ddca29ed747770a",
+        "rev": "32b1dbedfd77892a6e375737ef04d8efba634e9e",
         "type": "github"
       },
       "original": {
@@ -570,11 +570,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1678501303,
-        "narHash": "sha256-92s2NOlcvydz0Cxi1OOq/bs7SQc38TaqzuzdHsRANhA=",
+        "lastModified": 1679106165,
+        "narHash": "sha256-03Opt2yu4E/AIFjvlgib0/nhMn6B4B/t/nvwS2bzOGw=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "1c8200cdc4c830d937fbf8b19e1f3e83daf3370a",
+        "rev": "7313c06ac334d6262ddfe30a38b3abc3da6bd565",
         "type": "github"
       },
       "original": {
@@ -589,11 +589,11 @@
         "nixpkgs": "nixpkgs_5"
       },
       "locked": {
-        "lastModified": 1679537973,
-        "narHash": "sha256-R6borgcKeyMIjjPeeYsfo+mT8UdS+OwwbhhStdCfEjg=",
+        "lastModified": 1679624450,
+        "narHash": "sha256-wiDqUaklmc31E1+wz5sv52sMcWvZKsL1FBeGJCxz628=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "fbc7ae3f14d32e78c0e8d7865f865cc28a46b232",
+        "rev": "afbdcf305fd6f05f708fe76d52f24d37d066c251",
         "type": "github"
       },
       "original": {
diff --git a/nix-conf/home-manager/hwtr/nix.conf b/nix-conf/home-manager/hwtr/nix.conf
index cd5ea59..65a4873 100644
--- a/nix-conf/home-manager/hwtr/nix.conf
+++ b/nix-conf/home-manager/hwtr/nix.conf
@@ -1,4 +1,5 @@
 accept-flake-config = true
 experimental-features = nix-command flakes
 post-build-hook = /etc/nix/upload-to-cache.sh
+trusted-users = root htran hungtran hwtr
 
diff --git a/scripts/hm-switch.sh b/scripts/hm-switch.sh
index afc4854..c2df20d 100755
--- a/scripts/hm-switch.sh
+++ b/scripts/hm-switch.sh
@@ -17,6 +17,10 @@ if [ -f /etc/nix/nix.conf ]; then
 fi
 sudo cp "${HOME_MANAGER_DIR}/hwtr/nix.conf" /etc/nix/
 sudo cp "${SCRIPT_DIR}/upload-to-cache.sh" /etc/nix/
+sudo chmod +x /etc/nix/*.sh
+# Reload nix daemon so that new changes are applied.
+sudo launchctl stop org.nixos.nix-daemon
+sudo launchctl start org.nixos.nix-daemon
 
 # Mason is bad: it puts binaries onto xdg.data
 # let's make mason starts fresh, just in case we introduce RPATH hacks 
diff --git a/scripts/upload-to-cache.sh b/scripts/upload-to-cache.sh
old mode 100644
new mode 100755
index 5c42b4f..58597f4
--- a/scripts/upload-to-cache.sh
+++ b/scripts/upload-to-cache.sh
@@ -1,11 +1,11 @@
-#!/bin/sh
-
-set -eu
+#!/usr/bin/env sh
+set -eux
 set -f # disable globbing (/nix/store may contain glob chars)
 export IFS=' '
+PATH=/nix/var/nix/profiles/default/bin:$PATH
 
 # $OUT_PATHS when invoked by nix.settings.post-build-hook will be
 # space-separated paths to /nix/store/
 echo "Uploading paths" $OUT_PATHS
-exec nix copy --to "s3://example-nix-cache" $OUT_PATHS
+nix copy --to "ssh-ng://10.100.200.230" $OUT_PATHS