refac: split ci/cd into pieces

buildkite-ci.yaml

@@ -0,0 +1,64 @@
+steps:
+  - label: formatting diff
+    artifacts:
+      - formatting-before-vs-after.patch.txt
+    command:
+      - echo +++ Formatting - demo
+      - nix run . -- flake.nix
+
+      - echo --- Cloning nixpkgs
+      - git config --global user.email CI/CD
+      - git config --global user.name CI/CD
+      - git config --global --add safe.directory /data/nixpkgs/.git
+      - git clone --branch=master --depth 1 --origin=upstream file:///data/nixpkgs
+
+      - echo --- Formatting - before
+      - nix --tarball-ttl 1 run github:kamadorueda/alejandra -- nixpkgs 2>/dev/null
+      - git -C nixpkgs add .
+      - git -C nixpkgs commit -m formatting-before -q
+      - git -C nixpkgs branch formatting-before
+      - git -C nixpkgs reset --hard master~1
+
+      - echo --- Formatting - after
+      - nix run . -- nixpkgs 2>/dev/null
+      - git -C nixpkgs diff formatting-before > formatting-before-vs-after.patch.txt
+
+  - label: closure diff
+    artifacts:
+      - closure-before.txt
+      - closure-after.txt
+      - closure-before-vs-after.patch.txt
+    command:
+      - git config --global user.email CI/CD
+      - git config --global user.name CI/CD
+      - git config --global --add safe.directory /data/nixpkgs/.git
+      - git clone --branch=master --depth 1 --origin=upstream file:///data/nixpkgs
+
+      - echo --- Closure @ before
+      - nix-env --query --available --attr-path --drv-path --file nixpkgs --xml > closure-before.txt
+
+      - echo --- Formatting
+      - nix run . -- nixpkgs 2>/dev/null
+
+      - echo --- Closure @ after
+      - nix-env --query --available --attr-path --drv-path --file nixpkgs --xml > closure-after.txt
+
+      - echo +++ Closure diff
+      - git diff --no-index closure-before.txt closure-after.txt > closure-before-vs-after.patch.txt || true
+      - git diff --no-index closure-before.txt closure-after.txt --shortstat || true
+
+      - echo +++ Derivations count
+      - grep -c drvPath= closure-after.txt
+
+  - label: lint
+    command:
+      - echo --- Load environment
+      - direnv allow
+      - eval "$(direnv export bash)"
+      - echo +++ Run Linter
+      - cargo clippy
+
+  - label: flake check
+    command:
+      - echo +++
+      - nix flake check