fix(ci): route Buildkite jobs to v6 runners

.buildkite/pipeline.yml

@@ -1,6 +1,6 @@
 agents:
-  queue: "hetzner-linux-medium"
-  image: "evalops-platform-ci-v3"
+  queue: "hetzner-linux-heavy"
+  image: "evalops-platform-ci-v6"
 
 env:
   CI: "true"
@@ -22,7 +22,7 @@ steps:
           limit: 1
     command: |
       set -euo pipefail
-      cargo fmt --all -- --check
+      .buildkite/run-with-mise "rust@1.95.0" cargo fmt --all -- --check
       python3 scripts/test-repository-rules.py
       python3 scripts/test-deployment-images.py
       python3 scripts/test-release-readiness.py
@@ -42,7 +42,7 @@ steps:
           limit: 1
     agents:
       queue: "hetzner-linux-heavy"
-      image: "evalops-platform-ci-v3"
+      image: "evalops-platform-ci-v6"
     cache:
       name: "sandboxwich-tests-${BUILDKITE_PULL_REQUEST}"
       size: "50g"
@@ -95,7 +95,7 @@ steps:
         exit 1
       fi
       export SANDBOXWICH_TEST_POSTGRES_URL="postgres://postgres:postgres@127.0.0.1:$${host_port}/sandboxwich"
-      cargo test --workspace --locked
+      .buildkite/run-with-mise "rust@1.95.0" cargo test --workspace --locked
 
   - label: ":lint-roller: Clippy"
     key: "clippy"
@@ -111,12 +111,12 @@ steps:
           limit: 1
     agents:
       queue: "hetzner-linux-heavy"
-      image: "evalops-platform-ci-v3"
+      image: "evalops-platform-ci-v6"
     cache:
       name: "sandboxwich-clippy-${BUILDKITE_PULL_REQUEST}"
       size: "50g"
       paths: [".buildkite/cache"]
-    command: cargo clippy --workspace --all-targets --locked -- -D warnings
+    command: .buildkite/run-with-mise "rust@1.95.0" cargo clippy --workspace --all-targets --locked -- -D warnings
 
   - label: ":lock: Dependency audit"
     key: "audit"
@@ -130,8 +130,7 @@ steps:
           limit: 1
     command: |
       set -euo pipefail
-      cargo install cargo-audit --locked
-      cargo audit --ignore RUSTSEC-2023-0071
+      .buildkite/run-with-mise "rust@1.95.0" bash -c 'cargo install cargo-audit --locked && cargo audit --ignore RUSTSEC-2023-0071'
 
   - label: ":construction: Minimum Rust 1.95"
     key: "msrv"
@@ -147,4 +146,4 @@ steps:
       name: "sandboxwich-msrv-${BUILDKITE_PULL_REQUEST}"
       size: "30g"
       paths: [".buildkite/cache"]
-    command: cargo check --workspace --all-targets --locked
+    command: .buildkite/run-with-mise "rust@1.95.0" cargo check --workspace --all-targets --locked

.buildkite/run-with-mise

@@ -0,0 +1,64 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ $# -lt 2 ]]; then
+  echo "usage: $0 '<mise tool specs>' command [args...]" >&2
+  exit 2
+fi
+
+tool_list="$1"
+shift
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd -P)"
+cd "${repo_root}"
+
+mise_version="2026.4.24"
+mise_sha256="4ecf49b825741e1e3e8ff8c92ee242cf728da951d1b3592ef1c2f080201fa454"
+cache_root="${BUILDKITE_BUILD_CHECKOUT_PATH:-${repo_root}}/.buildkite/cache"
+runtime_root="${cache_root}/runtime"
+mkdir -p "${runtime_root}/bin" "${runtime_root}/mise/data" "${runtime_root}/mise/cache" \
+  "${runtime_root}/cargo/bin" "${runtime_root}/rustup" "${cache_root}/tmp"
+
+export MISE_DATA_DIR="${MISE_DATA_DIR:-${runtime_root}/mise/data}"
+export MISE_CACHE_DIR="${MISE_CACHE_DIR:-${runtime_root}/mise/cache}"
+export CARGO_HOME="${CARGO_HOME:-${runtime_root}/cargo}"
+export RUSTUP_HOME="${RUSTUP_HOME:-${runtime_root}/rustup}"
+export RUNNER_TEMP="${RUNNER_TEMP:-${cache_root}/tmp}"
+export CARGO_TARGET_DIR="${CARGO_TARGET_DIR:-${cache_root}/cargo-target}"
+export npm_config_cache="${npm_config_cache:-${cache_root}/npm}"
+export RUSTUP_INIT_SKIP_PATH_CHECK=yes
+export MISE_EXEC_AUTO_INSTALL=false
+export PATH="${runtime_root}/bin:${CARGO_HOME}/bin:${PATH}"
+
+mise_bin="${EVALOPS_MISE_BIN:-}"
+if [[ -z "${mise_bin}" ]] && command -v mise >/dev/null 2>&1; then
+  mise_bin="$(command -v mise)"
+fi
+if [[ -z "${mise_bin}" ]]; then
+  mise_bin="${runtime_root}/bin/mise"
+fi
+
+if [[ ! -x "${mise_bin}" ]]; then
+  mise_download="${cache_root}/mise-v${mise_version}-linux-x64"
+  if ! curl -fsSLo "${mise_download}" --retry 5 --retry-all-errors --retry-delay 3 \
+    --connect-timeout 15 \
+    "https://github.com/jdx/mise/releases/download/v${mise_version}/mise-v${mise_version}-linux-x64"; then
+    curl -fsSLo "${mise_download}" --retry 5 --retry-all-errors --retry-delay 3 \
+      --connect-timeout 15 \
+      "https://mise.jdx.dev/v${mise_version}/mise-v${mise_version}-linux-x64"
+  fi
+  printf '%s  %s\n' "${mise_sha256}" "${mise_download}" | sha256sum --check --status
+  install -m 0755 "${mise_download}" "${mise_bin}"
+fi
+
+read -r -a tools <<< "${tool_list}"
+for tool in "${tools[@]}"; do
+  "${mise_bin}" install "${tool}"
+done
+
+if [[ " ${tool_list} " == *" rust@"* ]]; then
+  "${mise_bin}" exec "${tools[@]}" -- rustup component add rustfmt clippy
+fi
+
+export EVALOPS_MISE_BIN="${mise_bin}"
+"${mise_bin}" exec "${tools[@]}" -- "$@"

scripts/test-repository-rules.py

@@ -39,8 +39,14 @@ def test_buildkite_rust_tests_are_postgres_backed(self) -> None:
             self.assertIn(marker, pipeline)
         self.assertIn("docker rm -f", pipeline)
 
-    def test_buildkite_heavy_jobs_use_all_connected_capacity(self) -> None:
+    def test_buildkite_jobs_route_to_the_connected_v6_heavy_pool(self) -> None:
         pipeline = (ROOT / ".buildkite/pipeline.yml").read_text()
+        self.assertEqual(pipeline.count('queue: "hetzner-linux-heavy"'), 3)
+        self.assertEqual(pipeline.count('image: "evalops-platform-ci-v6"'), 3)
+        self.assertNotIn("hetzner-linux-medium", pipeline)
+        self.assertNotIn("evalops-platform-ci-v3", pipeline)
+        self.assertGreaterEqual(pipeline.count('.buildkite/run-with-mise "rust@1.95.0"'), 5)
+        self.assertTrue((ROOT / ".buildkite/run-with-mise").is_file())
         self.assertEqual(
             pipeline.count('concurrency_group: "hetzner-linux-heavy-workloads"'),
             2,