diff --git a/.github/actions/devenv/action.yml b/.github/actions/devenv/action.yml
index d27314d..02a44db 100644
--- a/.github/actions/devenv/action.yml
+++ b/.github/actions/devenv/action.yml
@@ -11,6 +11,16 @@ inputs:
 runs:
   using: composite
   steps:
+    - name: free disk space
+      run: |
+        sudo rm -rf /usr/share/dotnet
+        sudo rm -rf /usr/local/lib/android
+        sudo rm -rf /opt/ghc
+        sudo rm -rf "/usr/local/share/boost"
+        sudo rm -rf "$AGENT_TOOLSDIRECTORY"
+        df -h
+      shell: bash
+
     - name: cache nix store
       uses: actions/cache@v4
       id: nix-cache
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6440326..bc9cc50 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -58,19 +58,10 @@ jobs:
     runs-on: ubuntu-24.04
     strategy:
       matrix:
-        version: ["1.79.0", ""]
+        version: ["1.81", ""]
     env:
       RUSTUP_TOOLCHAIN: ${{ matrix.version }}
     steps:
-      - name: free disk space
-        run: |
-          sudo rm -rf /usr/share/dotnet
-          sudo rm -rf /usr/local/lib/android
-          sudo rm -rf /opt/ghc
-          sudo rm -rf "/usr/local/share/boost"
-          sudo rm -rf "$AGENT_TOOLSDIRECTORY"
-          df -h
-
       - name: checkout repository
         uses: actions/checkout@v4
 
@@ -116,15 +107,6 @@ jobs:
     timeout-minutes: 60
     runs-on: ubuntu-24.04
     steps:
-      - name: free disk space
-        run: |
-          sudo rm -rf /usr/share/dotnet
-          sudo rm -rf /usr/local/lib/android
-          sudo rm -rf /opt/ghc
-          sudo rm -rf "/usr/local/share/boost"
-          sudo rm -rf "$AGENT_TOOLSDIRECTORY"
-          df -h
-
       - name: checkout repository
         uses: actions/checkout@v4
 
@@ -174,7 +156,7 @@ jobs:
     runs-on: ubuntu-24.04
     strategy:
       matrix:
-        version: ["1.79.0", ""]
+        version: ["1.81", ""]
     env:
       RUSTUP_TOOLCHAIN: ${{ matrix.version }}
     steps:
diff --git a/devenv.lock b/devenv.lock
index 1ff96b6..256d44a 100644
--- a/devenv.lock
+++ b/devenv.lock
@@ -53,16 +53,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1734669812,
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "099934f3d7ec89d14fa6a6950205fa7da5b55aba",
+        "lastModified": 1733477122,
+        "owner": "cachix",
+        "repo": "devenv-nixpkgs",
+        "rev": "7bd9e84d0452f6d2e63b6e6da29fe73fac951857",
         "type": "github"
       },
       "original": {
-        "owner": "NixOS",
-        "ref": "master",
-        "repo": "nixpkgs",
+        "owner": "cachix",
+        "ref": "rolling",
+        "repo": "devenv-nixpkgs",
         "type": "github"
       }
     },
diff --git a/devenv.yaml b/devenv.yaml
index d6723e8..cc5b10c 100644
--- a/devenv.yaml
+++ b/devenv.yaml
@@ -1,6 +1,6 @@
 inputs:
   nixpkgs:
-    url: github:NixOS/nixpkgs/master
+    url: github:cachix/devenv-nixpkgs/rolling
   rust-overlay:
     url: github:oxalica/rust-overlay
     overlays:
diff --git a/setup/cache-versions.json b/setup/cache-versions.json
index 6abaadc..dd59816 100644
--- a/setup/cache-versions.json
+++ b/setup/cache-versions.json
@@ -1,3 +1,3 @@
 {
-	"solana": "v2.1.5"
+	"solana": "v2.1.6"
 }