chore: migrate nullwatch to zig 0.16

.github/scripts/install-zig.sh

@@ -0,0 +1,166 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [ "$#" -ne 1 ]; then
+  echo "usage: $0 <zig-version>" >&2
+  exit 1
+fi
+
+version="$1"
+
+python_bin="${PYTHON:-python3}"
+if ! command -v "$python_bin" >/dev/null 2>&1; then
+  python_bin="python"
+fi
+if ! command -v "$python_bin" >/dev/null 2>&1; then
+  echo "python is required to install Zig" >&2
+  exit 1
+fi
+
+runner_os="${RUNNER_OS:-$(uname -s)}"
+runner_arch="${RUNNER_ARCH:-$(uname -m)}"
+
+case "$runner_os" in
+  Linux | linux)
+    zig_os="linux"
+    ;;
+  Darwin | macOS)
+    zig_os="macos"
+    ;;
+  Windows | MINGW* | MSYS* | CYGWIN*)
+    zig_os="windows"
+    ;;
+  *)
+    echo "unsupported runner OS: $runner_os" >&2
+    exit 1
+    ;;
+esac
+
+case "$runner_arch" in
+  X64 | x86_64 | amd64)
+    zig_arch="x86_64"
+    ;;
+  ARM64 | arm64 | aarch64)
+    zig_arch="aarch64"
+    ;;
+  *)
+    echo "unsupported runner architecture: $runner_arch" >&2
+    exit 1
+    ;;
+esac
+
+host_key="${zig_arch}-${zig_os}"
+tool_root="${RUNNER_TEMP:-${TMPDIR:-/tmp}}/nullwatch-zig"
+install_dir="${tool_root}/${version}/${host_key}"
+zig_bin="zig"
+if [ "$zig_os" = "windows" ]; then
+  zig_bin="zig.exe"
+fi
+
+if [ ! -x "${install_dir}/${zig_bin}" ]; then
+  mkdir -p "$(dirname "$install_dir")"
+
+  zig_metadata="$(
+    "$python_bin" - "$version" "$host_key" <<'PY'
+import json
+import sys
+import urllib.request
+
+version = sys.argv[1]
+host_key = sys.argv[2]
+
+with urllib.request.urlopen("https://ziglang.org/download/index.json") as response:
+    data = json.load(response)
+
+host = data.get(version, {}).get(host_key)
+if not host:
+    raise SystemExit(f"missing Zig download metadata for version={version!r} host={host_key!r}")
+
+archive_url = host.get("tarball") or host.get("zip")
+checksum = host.get("shasum") or ""
+if not archive_url:
+    raise SystemExit(f"missing archive URL for version={version!r} host={host_key!r}")
+
+print(archive_url)
+print(checksum)
+PY
+  )"
+
+  archive_url="$(printf '%s\n' "$zig_metadata" | sed -n '1p')"
+  expected_sha="$(printf '%s\n' "$zig_metadata" | sed -n '2p')"
+  if [ -z "$archive_url" ]; then
+    echo "failed to resolve Zig download URL" >&2
+    exit 1
+  fi
+
+  archive_name="${archive_url##*/}"
+  archive_dir="$(mktemp -d "${RUNNER_TEMP:-${TMPDIR:-/tmp}}/zig-archive.XXXXXX")"
+  archive_path="${archive_dir}/${archive_name}"
+  extract_dir="$(mktemp -d "${RUNNER_TEMP:-${TMPDIR:-/tmp}}/zig-extract.XXXXXX")"
+  trap 'rm -rf "$archive_dir"; rm -rf "$extract_dir"' EXIT
+
+  curl -fsSL --retry 3 --retry-all-errors "$archive_url" -o "$archive_path"
+
+  "$python_bin" - "$archive_path" "$expected_sha" <<'PY'
+import hashlib
+import sys
+
+path = sys.argv[1]
+expected = sys.argv[2].strip().lower()
+if not expected:
+    raise SystemExit(0)
+
+digest = hashlib.sha256()
+with open(path, "rb") as handle:
+    for chunk in iter(lambda: handle.read(1024 * 1024), b""):
+        digest.update(chunk)
+
+actual = digest.hexdigest().lower()
+if actual != expected:
+    raise SystemExit(f"checksum mismatch for {path}: expected {expected}, got {actual}")
+PY
+
+  "$python_bin" - "$archive_path" "$extract_dir" <<'PY'
+import pathlib
+import sys
+import tarfile
+import zipfile
+
+archive = pathlib.Path(sys.argv[1])
+destination = pathlib.Path(sys.argv[2])
+destination.mkdir(parents=True, exist_ok=True)
+
+def ensure_within_destination(relative_name: str) -> None:
+    target = (destination / relative_name).resolve()
+    if destination.resolve() not in target.parents and target != destination.resolve():
+        raise SystemExit(f"archive entry escapes destination: {relative_name}")
+
+if archive.suffix == ".zip":
+    with zipfile.ZipFile(archive) as handle:
+        for member in handle.namelist():
+            ensure_within_destination(member)
+        handle.extractall(destination)
+else:
+    with tarfile.open(archive, "r:*") as handle:
+        for member in handle.getnames():
+            ensure_within_destination(member)
+        handle.extractall(destination)
+PY
+
+  extracted_dir="$(find "$extract_dir" -mindepth 1 -maxdepth 1 -type d | head -n 1)"
+  if [ -z "$extracted_dir" ]; then
+    echo "failed to extract Zig archive: $archive_url" >&2
+    exit 1
+  fi
+
+  rm -rf "$install_dir"
+  mv "$extracted_dir" "$install_dir"
+fi
+
+if [ -n "${GITHUB_PATH:-}" ]; then
+  printf '%s\n' "$install_dir" >> "$GITHUB_PATH"
+else
+  echo "GITHUB_PATH is not set; add this directory to PATH manually: $install_dir" >&2
+fi
+
+"${install_dir}/${zig_bin}" version

.github/workflows/ci.yml

@@ -1,5 +1,9 @@
 name: CI
 
+env:
+  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
+  ZIG_VERSION: "0.16.0"
+
 on:
   push:
     branches: [main]
@@ -28,15 +32,13 @@ jobs:
             zig_target: x86_64-windows
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
-      - name: Install Zig 0.15.2
-        uses: mlugg/setup-zig@v2
-        with:
-          version: 0.15.2
+      - name: Install Zig 0.16.0
+        run: bash .github/scripts/install-zig.sh "${ZIG_VERSION}"
 
       - name: Cache Zig build outputs
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             .zig-cache
@@ -84,7 +86,7 @@ jobs:
 
       - name: Upload binary
         if: success()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: nullwatch-${{ matrix.target }}
           path: ci-artifacts/nullwatch${{ runner.os == 'Windows' && '.exe' || '' }}

.github/workflows/release.yml

@@ -1,5 +1,9 @@
 name: Release
 
+env:
+  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
+  ZIG_VERSION: "0.16.0"
+
 on:
   push:
     tags: ['v*']
@@ -45,12 +49,10 @@ jobs:
             ext: ".exe"
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
-      - name: Install Zig 0.15.2
-        uses: mlugg/setup-zig@v2
-        with:
-          version: 0.15.2
+      - name: Install Zig 0.16.0
+        run: bash .github/scripts/install-zig.sh "${ZIG_VERSION}"
 
       - name: Resolve build version
         id: version
@@ -65,7 +67,7 @@ jobs:
         run: zig build -Doptimize=ReleaseSmall -Dversion=${{ steps.version.outputs.value }} -Dtarget=${{ matrix.zig_target }}
 
       - name: Upload artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: nullwatch-${{ matrix.target }}
           path: zig-out/bin/nullwatch${{ matrix.ext }}
@@ -78,7 +80,7 @@ jobs:
         shell: bash
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
       - name: Create source archive
         run: |
@@ -92,7 +94,7 @@ jobs:
           echo "ARCHIVE_NAME=${archive_name}" >> "$GITHUB_ENV"
 
       - name: Upload source archive
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: nullwatch-source
           path: ${{ env.ARCHIVE_NAME }}
@@ -105,7 +107,7 @@ jobs:
       contents: write
 
     steps:
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@v8
 
       - name: Rename binaries
         run: |

build.zig.zon

@@ -2,7 +2,7 @@
     .name = .nullwatch,
     .version = "2026.3.16",
     .fingerprint = 0x331185e774b4ae7a,
-    .minimum_zig_version = "0.15.2",
+    .minimum_zig_version = "0.16.0",
     .paths = .{
         ".github",
         "build.zig",

src/api.zig

@@ -1,4 +1,5 @@
 const std = @import("std");
+const std_compat = @import("compat.zig");
 const domain = @import("domain.zig");
 const Store = @import("store.zig").Store;
 const version = @import("version.zig");
@@ -365,14 +366,14 @@ fn ingestOtlpScopeSpans(
             const run_id = (try firstOtlpAttributeText(ctx.allocator, attrs, &.{ "nullwatch.run_id", "nulltickets.run_id", "run_id" })) orelse
                 (try firstOtlpAttributeText(ctx.allocator, resource_attributes, &.{ "nullwatch.run_id", "nulltickets.run_id", "run_id" })) orelse
                 trace_id;
-            const source = (try firstOtlpAttributeText(ctx.allocator, resource_attributes, &.{ "service.name" })) orelse
+            const source = (try firstOtlpAttributeText(ctx.allocator, resource_attributes, &.{"service.name"})) orelse
                 scope_name orelse
                 "otlp";
             const operation = span.name orelse "unnamed";
-            const started_at_ms = parseUnixNanoMs(span.startTimeUnixNano) orelse std.time.milliTimestamp();
+            const started_at_ms = parseUnixNanoMs(span.startTimeUnixNano) orelse std_compat.time.milliTimestamp();
             const ended_at_ms = parseUnixNanoMs(span.endTimeUnixNano);
             const attributes_json = try otlpAttributesJson(ctx.allocator, attrs);
-            const success_text = try firstOtlpAttributeText(ctx.allocator, attrs, &.{ "success" });
+            const success_text = try firstOtlpAttributeText(ctx.allocator, attrs, &.{"success"});
             const status = determineOtlpStatus(span, success_text);
             const error_message = if (span.status) |status_payload|
                 status_payload.message orelse (try firstOtlpAttributeText(ctx.allocator, attrs, &.{ "error_message", "message", "detail" }))
@@ -626,10 +627,7 @@ fn jsonResponse(allocator: std.mem.Allocator, status_code: u16, value: anytype)
 }
 
 fn encodeJson(allocator: std.mem.Allocator, value: anytype) ![]u8 {
-    var out = std.io.Writer.Allocating.init(allocator);
-    defer out.deinit();
-    try std.json.Stringify.value(value, .{}, &out.writer);
-    return try out.toOwnedSlice();
+    return try std.json.Stringify.valueAlloc(allocator, value, .{});
 }
 
 fn statusTextFromCode(status_code: u16) []const u8 {