zig

name	zig
description	Work with Zig projects, builds, tests, and stdlib/API discovery. Use when editing Zig code, troubleshooting build/test failures, locating the stdlib with `zig env`, or validating code against the active Zig version instead of relying on memory.

Zig Skill

Use this skill for Zig code and Zig projects.

First step: inspect the active Zig installation

Run zig env before making assumptions.

Use it to find:

• .zig_exe — the Zig binary actually being used
• .version — the active Zig version
• .std_dir — the stdlib directory for that version
• .lib_dir — the Zig library root

Do not assume the project is using the Zig version you remember. Zig APIs can change between releases and master, including modules like std.ArrayList and std.io.

When a change depends on stdlib behavior, inspect the relevant file under the std_dir reported by zig env before editing.

Stdlib lookup

When you need stdlib details:

1. Run zig env.
2. Use the reported .std_dir.
3. Open or search the relevant file there instead of relying on memory.

Treat the stdlib as version-specific.

Testing

Always run tests with:

zig build test

Do not use zig test for project validation.

Reasons:

• zig build test includes modules wired through build.zig
• it exercises the project the way the build defines it
• it avoids drifting from the actual project setup

Run the full test suite every time.

Do not use --filter-test; do not try to partially run tests.

Validation steps

Some projects also define a zig build check step. Use it when present to validate the project state before or alongside zig build test.

Treat check as an additional validation step, not a replacement for tests.

Practical workflow

• Inspect build.zig and build.zig.zon when present.
• Check the active Zig version with zig env before changing code.
• Verify stdlib symbols against the current .std_dir.
• Use zig build check when the project defines it.
• Build and test with zig build test.
• If a test fails, fix the code for the active Zig version rather than assuming older APIs still apply.