diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 4f6d7ef..925a47c 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -17,7 +17,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: DeterminateSystems/nix-installer-action@main
-      - uses: DeterminateSystems/magic-nix-cache-action@main
       - id: set-matrix
         name: Generate Nix Matrix
         run: |
@@ -36,7 +35,10 @@ jobs:
           lfs: true
           submodules: 'recursive'
       - uses: DeterminateSystems/nix-installer-action@main
-      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - uses: cachix/cachix-action@v14
+        with:
+          name: mnn-rs
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
       - run: nix build -L '.#${{ matrix.attr }}'
 
   codecov:
diff --git a/flake.lock b/flake.lock
index 82b38ae..eec96e3 100644
--- a/flake.lock
+++ b/flake.lock
@@ -145,11 +145,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1731139594,
-        "narHash": "sha256-IigrKK3vYRpUu+HEjPL/phrfh7Ox881er1UEsZvw9Q4=",
+        "lastModified": 1731676054,
+        "narHash": "sha256-OZiZ3m8SCMfh3B6bfGC/Bm4x3qc1m2SVEAlkV6iY7Yg=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "76612b17c0ce71689921ca12d9ffdc9c23ce40b2",
+        "rev": "5e4fbfb6b3de1aa2872b76d49fafc942626e2add",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index 6643388..07b5971 100644
--- a/flake.nix
+++ b/flake.nix
@@ -65,10 +65,6 @@
                   lockFile = "${src}/Cargo.lock";
                 };
               };
-              cargo-llvm-cov = prev.cargo-llvm-cov.overrideAttrs (_: {
-                LLVM_COV = "${final.llvmPackages_19.llvm}/bin/llvm-cov";
-                LLVM_PROFDATA = "${final.llvmPackages_19.llvm}/bin/llvm-profdata";
-              });
             })
           ];
         };
@@ -222,6 +218,7 @@
                   git
                   git-lfs
                   llvm
+                  mnn
                   nushell
                   rust-bindgen
                   rustToolchainWithRustAnalyzer
diff --git a/mnn-sync/src/lib.rs b/mnn-sync/src/lib.rs
index 65b0ff9..1957da2 100644
--- a/mnn-sync/src/lib.rs
+++ b/mnn-sync/src/lib.rs
@@ -127,7 +127,7 @@ impl SessionRunnerState {
         tracing::info!("Unloading session");
         match core::mem::take(self) {
             Self::Loaded(sr) => {
-                let net = sr.unload()?;
+                let net = sr.unload();
                 *self = Self::Unloaded(net);
                 Ok(())
             }
@@ -221,11 +221,11 @@ impl SessionRunner {
         })
     }
 
-    pub fn unload(self) -> Result<mnn::Interpreter> {
+    pub fn unload(self) -> mnn::Interpreter {
         let session = self.session;
         let net = self.interpreter;
         drop(session);
-        Ok(net)
+        net
     }
 
     pub fn run_session(&mut self) -> Result<()> {