diff --git a/custom/modules/default.nix b/custom/modules/default.nix
index 8aeab7d..d338f67 100644
--- a/custom/modules/default.nix
+++ b/custom/modules/default.nix
@@ -6,14 +6,16 @@
 }:
 {
   boot = {
-    kernelPackages = pkgs.linuxPackagesFor (pkgs.callPackage ./kernel.nix {
-      inherit lib kernel-src;
-      structuredExtraConfig = { };
-      kernelPatches = [ ];
-      extraConfig = "";
-      features = { };
-      randstructSeed = null;
-    });
+    kernelPackages = pkgs.linuxPackagesFor (
+      pkgs.callPackage ./kernel.nix {
+        inherit lib kernel-src;
+        structuredExtraConfig = { };
+        kernelPatches = [ ];
+        extraConfig = "";
+        features = { };
+        randstructSeed = null;
+      }
+    );
     kernelPatches = [
       {
         name = "cpu";
@@ -107,8 +109,20 @@
           with lib.kernel;
           {
             IIO = no;
-            GOOGLE_FIRMWARE = lib.mkForce no;
+            #
             GNSS = no;
+            #
+            GOOGLE_FIRMWARE = lib.mkForce no;
+            #
+            TRACING = no;
+            FUNCTION_GRAPH_TRACER = no;
+            DYNAMIC_FTRACE = no;
+            #
+            FTRACE = lib.mkForce no;
+            FUNCTION_PROFILER = lib.mkForce no;
+            FUNCTION_TRACER = lib.mkForce no;
+            SCHED_TRACER = lib.mkForce no;
+            STACK_TRACER = lib.mkForce no;
           }
         );
       }
diff --git a/custom/modules/kernel.nix b/custom/modules/kernel.nix
index 210fc87..f9b4e22 100644
--- a/custom/modules/kernel.nix
+++ b/custom/modules/kernel.nix
@@ -74,7 +74,7 @@ let
     size = "100G"
   '';
   sccacheSetup = lib.optionalString enforceSccache ''
-    mkdir -p ${lib.escapeShellArg sccacheDir}
+    # mkdir -p ${lib.escapeShellArg sccacheDir}
     export SCCACHE_CONF=${lib.escapeShellArg sccacheConfig}
     ${lib.optionalString (sccacheServerUds != null) "export SCCACHE_SERVER_UDS=${lib.escapeShellArg sccacheServerUds}"}
   '';
@@ -83,7 +83,7 @@ let
     name: compiler:
     pkgs.writeShellScriptBin name ''
       set -euo pipefail
-      mkdir -p ${lib.escapeShellArg sccacheDir}
+      # mkdir -p ${lib.escapeShellArg sccacheDir}
       export SCCACHE_CONF=${lib.escapeShellArg sccacheConfig}
       ${lib.optionalString (sccacheServerUds != null) "export SCCACHE_SERVER_UDS=${lib.escapeShellArg sccacheServerUds}"}
       if [ -n "''${SCCACHE_ENFORCE_MARKER-}" ]; then
@@ -97,7 +97,7 @@ let
   hostcxxSccache = mkSccacheWrapper "c++" realHostCXX;
   rustcSccache = pkgs.writeShellScriptBin "rustc" ''
     set -euo pipefail
-    mkdir -p ${lib.escapeShellArg sccacheDir}
+    # mkdir -p ${lib.escapeShellArg sccacheDir}
     export SCCACHE_CONF=${lib.escapeShellArg sccacheConfig}
     ${lib.optionalString (sccacheServerUds != null) "export SCCACHE_SERVER_UDS=${lib.escapeShellArg sccacheServerUds}"}
     if [ -n "''${SCCACHE_ENFORCE_MARKER-}" ]; then
@@ -108,7 +108,7 @@ let
 
   hostrustcSccache = pkgs.writeShellScriptBin "rustc" ''
     set -euo pipefail
-    mkdir -p ${lib.escapeShellArg sccacheDir}
+    # mkdir -p ${lib.escapeShellArg sccacheDir}
     export SCCACHE_CONF=${lib.escapeShellArg sccacheConfig}
     ${lib.optionalString (sccacheServerUds != null) "export SCCACHE_SERVER_UDS=${lib.escapeShellArg sccacheServerUds}"}
     if [ -n "''${SCCACHE_ENFORCE_MARKER-}" ]; then
diff --git a/flake.lock b/flake.lock
index 60ec9c0..329724f 100644
--- a/flake.lock
+++ b/flake.lock
@@ -46,11 +46,11 @@
         "nixpkgs": "nixpkgs"
       },
       "locked": {
-        "lastModified": 1773711063,
-        "narHash": "sha256-cLdaclWQ1ValFyHUuTUoTbuglryGNvSecVnLJ3GVrng=",
+        "lastModified": 1773875165,
+        "narHash": "sha256-pPSaTA/vwZRmH/oXGkx1GLF4kFAdCXRzwFNJlLlCTQc=",
         "owner": "sadjow",
         "repo": "claude-code-nix",
-        "rev": "66126ac5b750446573376638ce5361bc97b9aa81",
+        "rev": "c2186a8096247357c77aaa067e14ee39ce45ac8d",
         "type": "github"
       },
       "original": {
@@ -451,11 +451,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1773681856,
-        "narHash": "sha256-+bRqxoFCJFO9ZTFhcCkzNXbDT3b8AEk88fyjB7Is6eo=",
+        "lastModified": 1773810247,
+        "narHash": "sha256-6Vz1Thy/1s7z+Rq5OfkWOBAdV4eD+OrvDs10yH6xJzQ=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "57d5560ee92a424fb71fde800acd6ed2c725dfce",
+        "rev": "d47357a4c806d18a3e853ad2699eaec3c01622e7",
         "type": "github"
       },
       "original": {
@@ -540,16 +540,16 @@
     "kernel-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1773493865,
-        "narHash": "sha256-3f17iyo1Dh96KKPYLAGFAUQxVZrxe06ne2uy/Y3FPuE=",
+        "lastModified": 1773844285,
+        "narHash": "sha256-vOF2HIA1J5Ktzt2aYqGPBv3AEQb0ziORKRQIOj+6h04=",
         "ref": "refs/heads/drm-tip",
-        "rev": "bbe6ae2e40f59b05f04a75989b3b3bbb005342a2",
+        "rev": "61409ba11a36fa5aff4ce0f0086a6026a43c5bce",
         "shallow": true,
         "type": "git",
         "url": "https://gitlab.freedesktop.org/drm/tip.git"
       },
       "original": {
-        "rev": "bbe6ae2e40f59b05f04a75989b3b3bbb005342a2",
+        "rev": "61409ba11a36fa5aff4ce0f0086a6026a43c5bce",
         "shallow": true,
         "type": "git",
         "url": "https://gitlab.freedesktop.org/drm/tip.git"
@@ -611,11 +611,11 @@
         "xwayland-satellite-unstable": "xwayland-satellite-unstable"
       },
       "locked": {
-        "lastModified": 1773725889,
-        "narHash": "sha256-htkVJrtaWJS7wQSXg8d26RR6jF3Iab2bYTNfvTgv05Q=",
+        "lastModified": 1773889880,
+        "narHash": "sha256-cu23CGP+mD2wKPKaoGM7evZ1dXfjd+cjryqqqx2HloE=",
         "owner": "sodiboo",
         "repo": "niri-flake",
-        "rev": "9987baf8f935a1b3b2aa89a44c13b3239ecc640e",
+        "rev": "63767d4572eb2e3da5e68f68de77d8f2cdeca8dd",
         "type": "github"
       },
       "original": {
@@ -695,11 +695,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1773597492,
-        "narHash": "sha256-hQ284SkIeNaeyud+LS0WVLX+WL2rxcVZLFEaK0e03zg=",
+        "lastModified": 1773628058,
+        "narHash": "sha256-hpXH0z3K9xv0fHaje136KY872VT2T5uwxtezlAskQgY=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "a07d4ce6bee67d7c838a8a5796e75dff9caa21ef",
+        "rev": "f8573b9c935cfaa162dd62cc9e75ae2db86f85df",
         "type": "github"
       },
       "original": {
@@ -726,11 +726,11 @@
     },
     "nixpkgs-stable": {
       "locked": {
-        "lastModified": 1773705440,
-        "narHash": "sha256-xB30bbAp0e7ogSEYyc126mAJMt4FRFh8wtm6ADE1xuM=",
+        "lastModified": 1773814637,
+        "narHash": "sha256-GNU+ooRmrHLfjlMsKdn0prEKVa0faVanm0jrgu1J/gY=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "48652e9d5aea46e555b3df87354280d4f29cd3a3",
+        "rev": "fea3b367d61c1a6592bc47c72f40a9f3e6a53e96",
         "type": "github"
       },
       "original": {
@@ -787,11 +787,11 @@
     },
     "nixpkgs_5": {
       "locked": {
-        "lastModified": 1773646010,
-        "narHash": "sha256-iYrs97hS7p5u4lQzuNWzuALGIOdkPXvjz7bviiBjUu8=",
+        "lastModified": 1773821835,
+        "narHash": "sha256-TJ3lSQtW0E2JrznGVm8hOQGVpXjJyXY2guAxku2O9A4=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "5b2c2d84341b2afb5647081c1386a80d7a8d8605",
+        "rev": "b40629efe5d6ec48dd1efba650c797ddbd39ace0",
         "type": "github"
       },
       "original": {
@@ -1015,11 +1015,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1773673214,
-        "narHash": "sha256-cjdDXKuMFO9mtBr1jCQsfKMsPBUdbG/8Hklhym29X5k=",
+        "lastModified": 1773852796,
+        "narHash": "sha256-aEriBf9qkKeUoICKuxOj9e1GE8PZEnKke83+TzXpBT8=",
         "owner": "mozilla",
         "repo": "sccache",
-        "rev": "7b751fccd4e3dfc4e16564f967dae306649dee0b",
+        "rev": "8d6cab9ee9356ff4054409c60f7a607cb798de03",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index fa5f52c..a9368b1 100644
--- a/flake.nix
+++ b/flake.nix
@@ -24,7 +24,7 @@
     nix-flatpak.url = "github:gmodena/nix-flatpak/latest";
     kernel-src = {
       # url = "git+https://gitlab.freedesktop.org/drm/tip.git?shallow=1";
-      url = "git+https://gitlab.freedesktop.org/drm/tip.git?rev=bbe6ae2e40f59b05f04a75989b3b3bbb005342a2&shallow=1";
+      url = "git+https://gitlab.freedesktop.org/drm/tip.git?rev=61409ba11a36fa5aff4ce0f0086a6026a43c5bce&shallow=1";
       flake = false;
     };
     sccache = {
diff --git a/todo.md b/todo.md
index 4dd939b..be09aea 100644
--- a/todo.md
+++ b/todo.md
@@ -25,6 +25,8 @@
 - The new ccache-style `sccacheWrapper` / `sccacheStdenv` path evaluates successfully.
 - `intel-sycl.stdenv.cc` now also evaluates successfully with the ccache-style `sccache.links` replacement in place.
 - The custom kernel helper now normalizes config-only `kernelPatches` entries to `{ patch = null; ... }` before calling `buildLinux`, which fixes `devenv shell -- build` failing during kernel evaluation.
+- The kernel build does invoke `sccache` during live builds, but relying on the in-sandbox wrapper to create `/var/cache/sccache/nix-builds/kernel` made host-side observation ambiguous.
+- The host NixOS config should create and expose `/var/cache/sccache/nix-builds/{packages,kernel}` explicitly so sandboxed builds and host-side inspection see the same cache paths.
 
 ## Next Checks