chore: upgrade to Zig 0.16.0 by lodekeeper-z · Pull Request #4 · ChainSafe/blst.zig

lodekeeper-z · 2026-03-19T19:14:29Z

Upgrade to Zig 0.16.0-dev (master) — part of the lodestar-z Zig master upgrade effort.

Key changes:

std.io → std.Io migration
std.Io.Dir methods now require explicit io parameter
Build system changes for 0.16 compatibility

🤖 Generated with AI assistance

- std.ArrayList: .init(alloc) → .empty + explicit allocator on each method - addCSourceFiles moved from Compile to Module (lib.root_module) 🤖 Generated with AI assistance

Zig's bundled clang does not automatically define __APPLE__ when compiling .S assembly files, even on a macOS target. blst's build/assembly.S uses #ifdef __APPLE__ to select the mach-o ARM64 symbol variants; without this define, the #elif __ELF__ branch is taken instead and the mach-o symbols (_mulx_mont_384, _fromx_mont_256, etc.) are never assembled, causing undefined-symbol linker errors on Apple Silicon with Zig 0.16+. 🤖 Generated with AI assistance

addCMacro only passes -D flags to the Zig compiler, not to clang when compiling C/assembly sources via addCSourceFiles. The fix for macOS ARM64 blst assembly must be in c_flags so clang receives the -D__APPLE__=1 flag. 🤖 Generated with AI assistance

std.Target.x86.featureSetHas() called on a non-x86 CpuFeatureSet is undefined behavior — feature enum indices are arch-specific, so x86's .adx (index 13) may map to an unrelated ARM64 feature (balance_fp_ops) that is enabled on Apple Silicon. This incorrectly sets __ADX__, causing server.c to reference ctx_*-prefixed symbols via vect.h macros, while the ARM64 mach-o assembly only defines ct_*-prefixed symbols → undefined symbol linker errors on Apple Silicon. Also remove the spurious -D__APPLE__ c_flag: clang already defines __APPLE__ natively when building for macOS. 🤖 Generated with AI assistance

Copilot

Pull request overview

Upgrades the build script and repo ignore patterns to align with Zig 0.16.0-dev build/stdlib API changes as part of the Zig master upgrade effort.

Changes:

Migrates std.ArrayList usage to the new .empty / append(allocator, ...) / deinit(allocator) APIs.
Updates C source inclusion to use lib.root_module.addCSourceFiles and adds a safe arch guard around the __ADX__ macro definition.
Ignores zig-pkg/ in .gitignore.

Reviewed changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated no comments.

File	Description
build.zig	Updates build logic and flags handling for Zig 0.16 API changes; adds an x86_64-only guard for ADX feature probing.
.gitignore	Adds `zig-pkg/` to ignored build/package artifacts.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot

Pull request overview

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot

Pull request overview

Copilot reviewed 3 out of 4 changed files in this pull request and generated 2 comments.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-04-17T07:19:10Z

    .fingerprint = 0x97ffb139ce317072, // Changing this has security and trust implications.

-    .minimum_zig_version = "0.14.1",
+    .minimum_zig_version = "0.16.0",


PR description says upgrade to Zig 0.16.0-dev (master), but the package minimum Zig version is set to the stable-looking "0.16.0". If this repo is intended to track master/nightly, align this to a dev identifier (or update the PR description if the intent is the 0.16.0 release) to avoid consumers/CI trying to use a different toolchain than expected.

Copilot · 2026-04-17T07:19:11Z

 env:
-  ZIG_VERSION: 0.14.1
+  ZIG_VERSION: 0.16.0



PR description mentions Zig 0.16.0-dev (master), but CI pins ZIG_VERSION to "0.16.0". Please align CI with the intended toolchain (e.g., master/nightly vs a released 0.16.0) so CI reliably matches the minimum/toolchain expected by the package.

Four of the five Zig-0.16-upgrade PRs on our dependency forks have merged into ChainSafe upstream main: * ChainSafe/blst.zig#4 → 6ad139a * ChainSafe/hashtree-z#10 → 56e406f * ChainSafe/snappy.zig#5 → 7139424 * ChainSafe/zig-yaml#1 → b74f4e8 Switch from `lodekeeper-z/<repo>?ref=chore/zig-master` to the merged commit on `ChainSafe/<repo>` main for each. Content is identical so the existing `hash` fields stay valid. `zapi` (ChainSafe/zapi#9) is still open upstream — bump the `lodekeeper-z/zapi` commit pointer to the current PR head (fefb88ebf5c9) which includes the latest port/refactor work; TODO note to switch to ChainSafe/zapi once ChainSafe#9 merges.

## Motivation Get the codebase cleanly compatible with **Zig 0.16.0** release, following the new "explicit `io` everywhere, no hidden global state" design — without changing runtime behavior. ## Description - **`std.Io`** — File/Dir operations, `Mutex`/`Condition`/`Event` (cancelable vs uncancelable split), entropy via `io.random`/`io.randomSecure`, timestamps via `std.Io.Timestamp` - **ArrayList unmanaged** — allocator threaded through `deinit`/`append`/`resize`/`ensureCapacity`/`clone`; replace `items.len = N` hacks with `resize` / `expandToCapacity` / `appendNTimesAssumeCapacity` (preserves semantics, matches `initCapacity`'s Precise allocation) - **Struct builder** — `@Type(.@"struct" = ...)` → `@Struct(names, types, attrs)` builtin in `ssz/type/container.zig` - **Copy-elision workaround** — `std.Io` 0.16 result-location semantics pre-write the union tag of the assignment target, so reads from `self.state.init_group.*` during RHS evaluation would observe the new variant. Snapshot pre-upgrade fields to locals in `state_transition.zig` fork-upgrade chain and `era/Writer.zig` - **ThreadPool** — `io` is a parameter on `init`/`deinit`/`verifyMultipleAggregateSignatures`/`aggregateVerify` (not a stored field); normal paths use cancelable `lock`; shutdown + `submitAndWait.done.wait` stay uncancelable with comments explaining the invariant - **Shared `src/time.zig`** — `timestampNow` / `since (Duration)` / `durationSeconds`, replacing four duplicated helper pairs across `state_transition` and `bench` - **IO signature convention** — `(allocator?, io, file, ...)` applied consistently to `e2s.*` and `era.*` - **Reader API polish** — `takeArray` (zero-copy) + `readSliceAll` where appropriate; drop single-buffer `readVecAll` and `catch |err| return err` - **Other**: `RefCount` comptime-reflect on wrapped T's deinit arity (1-arg vs 2-arg) so 0.16 unmanaged `ArrayList` and project types with stored allocators both work; `sanitize_c = .trap` on blst artifact so Debug fuzz builds link without `libubsan`; untrack 426 stale `test/fuzz/zig-pkg/` entries from the git index - **CI**: `ZIG_VERSION` bumped `0.14.1 → 0.16.0`; `zbuild` sync-check + `build-examples` jobs temporarily commented out pending upstream Zig 0.16 support ## Dependency PRs Each Zig 0.16 upgrade landed as a dedicated PR on the upstream repo. `build.zig.zon` points at `lodekeeper-z` forks on the `chore/zig-master` branch until these merge and cut releases: | Dependency | Upstream PR | |---|---| | `blst` | [ChainSafe/blst.zig#4](ChainSafe/blst.zig#4) | | `hashtree` | [ChainSafe/hashtree-z#10](ChainSafe/hashtree-z#10) | | `snappy` | [ChainSafe/snappy.zig#5](ChainSafe/snappy.zig#5) | | `yaml` | [ChainSafe/zig-yaml#1](ChainSafe/zig-yaml#1) | | `zapi` | [ChainSafe/zapi#9](ChainSafe/zapi#9) | | `httpz` (disabled) | [karlseguin/http.zig#191](karlseguin/http.zig#191) |

chore: upgrade to Zig 0.16.0-dev (master)

c58262a

- std.ArrayList: .init(alloc) → .empty + explicit allocator on each method - addCSourceFiles moved from Compile to Module (lib.root_module) 🤖 Generated with AI assistance

lodekeeper-z mentioned this pull request Mar 19, 2026

chore: upgrade to Zig 0.16.0-dev (master) ChainSafe/lodestar-z#252

Draft

lodekeeper-z and others added 4 commits March 19, 2026 20:36

fix: clean up duplicate .gitignore entries

e9e8b35

GrapeBaBa marked this pull request as ready for review April 16, 2026 11:29

Copilot AI review requested due to automatic review settings April 16, 2026 11:29

Copilot started reviewing on behalf of GrapeBaBa April 16, 2026 11:29 View session

Copilot AI reviewed Apr 16, 2026

View reviewed changes

ci: update Zig version to 0.16.0

a9a19df

GrapeBaBa requested a review from Copilot April 16, 2026 13:47

Copilot started reviewing on behalf of GrapeBaBa April 16, 2026 13:47 View session

Copilot AI reviewed Apr 16, 2026

View reviewed changes

Comment thread build.zig

Comment thread .github/workflows/ci.yml

GrapeBaBa added 2 commits April 16, 2026 23:05

style: use trailing slash for directory entries in .gitignore

3c625e5

chore: set minimum_zig_version to 0.16.0

a647da8

GrapeBaBa changed the title ~~chore: upgrade to Zig 0.16.0-dev (master)~~ chore: upgrade to Zig 0.16.0 Apr 17, 2026

GrapeBaBa requested review from Copilot, spiral-ladder and wemeetagain April 17, 2026 07:17

Copilot started reviewing on behalf of GrapeBaBa April 17, 2026 07:17 View session

Copilot AI reviewed Apr 17, 2026

View reviewed changes

wemeetagain approved these changes Apr 17, 2026

View reviewed changes

GrapeBaBa mentioned this pull request Apr 20, 2026

chore: upgrade to Zig 0.16 ChainSafe/lodestar-z#319

Merged

wemeetagain merged commit 6ad139a into ChainSafe:main Apr 20, 2026
7 checks passed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

chore: upgrade to Zig 0.16.0#4

chore: upgrade to Zig 0.16.0#4
wemeetagain merged 8 commits into
ChainSafe:mainfrom
lodekeeper-z:chore/zig-master

lodekeeper-z commented Mar 19, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI left a comment

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Apr 17, 2026

Uh oh!

Copilot AI Apr 17, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

Conversation

lodekeeper-z commented Mar 19, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Uh oh!

Copilot AI Apr 17, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 17, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants