diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 4d33b8b1..81246706 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -10,6 +10,10 @@ concurrency:
   group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
+
 jobs:
   build-nix:
     runs-on: ubuntu-latest
@@ -29,20 +33,16 @@ jobs:
               - '**/*.go'
               - 'integration_test/'
               - 'config-example.yaml'
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.files == 'true'
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.files == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: Check vendor hash
         id: vendorhash
         if: steps.changed-files.outputs.files == 'true'
         run: |
-          nix develop --fallback --command -- go run ./cmd/vendorhash check | tee check-result
+          go run ./cmd/vendorhash check | tee check-result
           {
             grep '^expected_sri=' check-result || true
             grep '^actual_sri='   check-result || true
@@ -81,17 +81,13 @@ jobs:
           - "GOARCH=amd64 GOOS=darwin"
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
 
       - name: Run go cross compile
         env:
           CGO_ENABLED: 0
-        run: env ${{ matrix.env }} nix develop --fallback --command -- go build -o "headscale"
+        run: env ${{ matrix.env }} go build -o "headscale"
           ./cmd/headscale
       - uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
         with:
diff --git a/.github/workflows/check-generated.yml b/.github/workflows/check-generated.yml
index 4b463fcc..fffc3da0 100644
--- a/.github/workflows/check-generated.yml
+++ b/.github/workflows/check-generated.yml
@@ -12,6 +12,10 @@ concurrency:
   group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
+
 jobs:
   check-generated:
     runs-on: ubuntu-latest
@@ -29,17 +33,14 @@ jobs:
               - 'go.*'
               - '**/*.go'
               - 'tools/**'
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.files == 'true'
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.files == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix', '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: Run make generate
         if: steps.changed-files.outputs.files == 'true'
-        run: nix develop --fallback --command -- make generate
+        run: make generate
 
       - name: Check for uncommitted changes
         if: steps.changed-files.outputs.files == 'true'
diff --git a/.github/workflows/check-tests.yaml b/.github/workflows/check-tests.yaml
index df5b857c..b7301173 100644
--- a/.github/workflows/check-tests.yaml
+++ b/.github/workflows/check-tests.yaml
@@ -6,6 +6,10 @@ concurrency:
   group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
+
 jobs:
   check-tests:
     runs-on: ubuntu-latest
@@ -24,19 +28,15 @@ jobs:
               - '**/*.go'
               - 'integration_test/'
               - 'config-example.yaml'
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.files == 'true'
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.files == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: Generate and check integration tests
         if: steps.changed-files.outputs.files == 'true'
         run: |
-          nix develop --fallback --command bash -c "cd .github/workflows && go generate"
+          (cd .github/workflows && go generate)
           git diff --exit-code .github/workflows/test-integration.yaml
 
       - name: Show missing tests
diff --git a/.github/workflows/container-main.yml b/.github/workflows/container-main.yml
index 71710e9f..e2ebe6fc 100644
--- a/.github/workflows/container-main.yml
+++ b/.github/workflows/container-main.yml
@@ -16,6 +16,10 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.sha }}
   cancel-in-progress: true
 
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
+
 jobs:
   container:
     if: github.repository == 'juanfont/headscale'
@@ -40,12 +44,8 @@ jobs:
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
 
       - name: Set commit timestamp
         run: echo "SOURCE_DATE_EPOCH=$(git log -1 --format=%ct)" >> $GITHUB_ENV
@@ -56,7 +56,7 @@ jobs:
           KO_DEFAULTBASEIMAGE: gcr.io/distroless/base-debian13
           CGO_ENABLED: "0"
         run: |
-          nix develop --fallback --command -- ko build \
+          ko build \
             --bare \
             --platform=linux/amd64,linux/arm64 \
             --tags=main-${GITHUB_SHA::7},development \
@@ -68,7 +68,7 @@ jobs:
           KO_DEFAULTBASEIMAGE: gcr.io/distroless/base-debian13
           CGO_ENABLED: "0"
         run: |
-          nix develop --fallback --command -- ko build \
+          ko build \
             --bare \
             --platform=linux/amd64,linux/arm64 \
             --tags=main-${GITHUB_SHA::7},development \
@@ -92,19 +92,15 @@ jobs:
       - name: Checkout
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
 
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
 
       - name: Build binary
         env:
           CGO_ENABLED: "0"
           GOOS: ${{ matrix.goos }}
           GOARCH: ${{ matrix.goarch }}
-        run: nix develop --fallback --command -- go build -o headscale ./cmd/headscale
+        run: go build -o headscale ./cmd/headscale
 
       - uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
         with:
diff --git a/.github/workflows/gc.yml b/.github/workflows/gc.yml
new file mode 100644
index 00000000..9df7a037
--- /dev/null
+++ b/.github/workflows/gc.yml
@@ -0,0 +1,39 @@
+name: Cache GC
+
+# Garbage collection for the hestia binary cache. Must run on the default
+# branch: a PR job's cache scope is read-only towards the default branch and
+# dies with the PR, but the default-branch scope grows forever without GC.
+
+concurrency:
+  group: hestia-gc
+  cancel-in-progress: false
+
+on:
+  schedule:
+    # Daily, off-peak (UTC).
+    - cron: "23 3 * * *"
+  workflow_dispatch:
+    inputs:
+      dry-run:
+        description: Plan only; do not repack, touch, or delete anything.
+        type: boolean
+        default: false
+
+permissions:
+  contents: read
+
+jobs:
+  gc:
+    runs-on: ubuntu-latest
+    permissions:
+      # REST cache deletes need actions:write.
+      actions: write
+      contents: read
+    steps:
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
+      - name: Run garbage collection
+        run: '"${HESTIA_BIN}" gc ${{ inputs.dry-run && ''--dry-run'' || '''' }}'
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index ed809ac5..617355d6 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -6,6 +6,10 @@ concurrency:
   group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
+
 jobs:
   golangci-lint:
     runs-on: ubuntu-latest
@@ -24,18 +28,14 @@ jobs:
               - '**/*.go'
               - 'integration_test/'
               - 'config-example.yaml'
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.files == 'true'
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.files == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: golangci-lint
         if: steps.changed-files.outputs.files == 'true'
-        run: nix develop --fallback --command -- golangci-lint run
+        run: golangci-lint run
           --new-from-rev=${{github.event.pull_request.base.sha}}
           --output.text.path=stdout
           --output.text.print-linter-name
@@ -64,16 +64,12 @@ jobs:
               - '**/*.css'
               - '**/*.scss'
               - '**/*.html'
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.files == 'true'
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.files == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: Prettify code
         if: steps.changed-files.outputs.files == 'true'
-        run: nix develop --fallback --command -- prettier --no-error-on-unmatched-pattern
+        run: prettier --no-error-on-unmatched-pattern
           --ignore-unknown --check **/*.{ts,js,md,yaml,yml,sass,css,scss,html}
diff --git a/.github/workflows/nix-module-test.yml b/.github/workflows/nix-module-test.yml
index 03fe1191..1a7fbcc8 100644
--- a/.github/workflows/nix-module-test.yml
+++ b/.github/workflows/nix-module-test.yml
@@ -38,15 +38,11 @@ jobs:
               - 'cmd/**'
               - 'hscontrol/**'
 
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.nix == 'true' || steps.changed-files.outputs.go == 'true'
 
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.nix == 'true' || steps.changed-files.outputs.go == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: Run NixOS module tests
         if: steps.changed-files.outputs.nix == 'true' || steps.changed-files.outputs.go == 'true'
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 2d8c172b..349ad53d 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -7,6 +7,10 @@ on:
       - "*" # triggers only if push new tag version
   workflow_dispatch:
 
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
+
 jobs:
   goreleaser:
     if: github.repository == 'juanfont/headscale'
@@ -30,14 +34,10 @@ jobs:
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
 
       - name: Run goreleaser
-        run: nix develop --fallback --command -- goreleaser release --clean
+        run: goreleaser release --clean
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/test-integration.yaml b/.github/workflows/test-integration.yaml
index bfa13e34..bfdb3f57 100644
--- a/.github/workflows/test-integration.yaml
+++ b/.github/workflows/test-integration.yaml
@@ -6,6 +6,9 @@ on: [pull_request]
 concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
 jobs:
   # build: Builds binaries and Docker images once, uploads as artifacts for reuse.
   # build-postgres: Pulls postgres image separately to avoid Docker Hub rate limits.
@@ -36,23 +39,18 @@ jobs:
               - '.github/workflows/test-integration.yaml'
               - '.github/workflows/integration-test-template.yml'
               - 'Dockerfile.*'
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.files == 'true'
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.files == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix', '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
       - name: Build binaries and warm Go cache
         if: steps.changed-files.outputs.files == 'true'
         run: |
           # Build all Go binaries in one nix shell to maximize cache reuse
-          nix develop --fallback --command -- bash -c '
-            go build -o hi ./cmd/hi
-            CGO_ENABLED=0 GOOS=linux go build -o headscale ./cmd/headscale
-            # Build integration test binary to warm the cache with all dependencies
-            go test -c ./integration -o /dev/null 2>/dev/null || true
-          '
+          go build -o hi ./cmd/hi
+          CGO_ENABLED=0 GOOS=linux go build -o headscale ./cmd/headscale
+          # Build integration test binary to warm the cache with all dependencies
+          go test -c ./integration -o /dev/null 2>/dev/null || true
       - name: Upload hi binary
         if: steps.changed-files.outputs.files == 'true'
         uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
@@ -128,6 +126,7 @@ jobs:
     if: needs.build.outputs.files-changed == 'true'
     steps:
       - name: Force overlay2 storage driver
+        shell: bash
         run: |
           sudo mkdir -p /etc/docker
           echo '{"storage-driver":"overlay2"}' | sudo tee /etc/docker/daemon.json
@@ -143,6 +142,7 @@ jobs:
           username: ${{ env.DOCKERHUB_USERNAME }}
           password: ${{ env.DOCKERHUB_TOKEN }}
       - name: Pull and save postgres image
+        shell: bash
         run: |
           docker pull postgres:latest
           docker tag postgres:latest postgres:${{ github.sha }}
@@ -159,11 +159,8 @@ jobs:
     if: needs.build.outputs.files-changed == 'true'
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix', '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
       - name: Force overlay2 storage driver
         run: |
           sudo mkdir -p /etc/docker
@@ -182,7 +179,7 @@ jobs:
       - name: List Tailscale versions to pre-pull
         id: versions
         run: |
-          versions=$(nix develop --fallback --command go run ./cmd/hi list-versions --set=must --exclude=head)
+          versions=$(go run ./cmd/hi list-versions --set=must --exclude=head)
           echo "versions=${versions}" >> "$GITHUB_OUTPUT"
           echo "Pre-pulling: ${versions}"
       - name: Pull Tailscale images
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 911f0057..dadacddc 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -6,6 +6,10 @@ concurrency:
   group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
+defaults:
+  run:
+    shell: nix develop --fallback --command bash -e {0}
+
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -27,14 +31,10 @@ jobs:
               - 'integration_test/'
               - 'config-example.yaml'
 
-      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
+      - uses: NixOS/nix-installer-action@6b8548fe06acfb0155a50ab5d561accb215764cc # main
         if: steps.changed-files.outputs.files == 'true'
-      - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
+      - uses: Mic92/hestia/action@ff07bb902a9968ac0c3d0e51d90a606662a375d8 # main
         if: steps.changed-files.outputs.files == 'true'
-        with:
-          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
-            '**/flake.lock') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: Run tests
         if: steps.changed-files.outputs.files == 'true'
@@ -44,4 +44,4 @@ jobs:
           # some of the database migration tests.
           LC_ALL: "en_US.UTF-8"
           LC_CTYPE: "en_US.UTF-8"
-        run: nix develop --fallback --command -- gotestsum
+        run: gotestsum