v0.5.0 — Zig 0.16.0 migration

Highlights

• Zig 0.16.0 + zwasm v1.11.0 — full toolchain bump (D111). All std.Io reshapes centralized behind src/runtime/io_default.zig, so module-level mutexes / condvars / sleeps / env lookups don't have to thread io through every call site.
• Performance (ReleaseSafe, macOS aarch64): Binary 4.12 MB / Startup 4.1 ms / RSS 8.2 MB
• Green gate: 1324/1324 unit tests, 83 cljw test namespaces, 6 wasm e2e, deps.edn e2e — all passing.

Toolchain

• build.zig.zon minimum_zig_version → 0.16.0
• flake.nix pin → 0.16.0 (sha256 mirrored from zwasm)
• .github/workflows/{ci,nightly,release}.yml setup-zig version pin → 0.16.0
• link_libc = true enabled (inherited from zwasm v1.11.0). Several stdlib removals (std.posix.{getenv,write,isatty,mprotect}, std.fs.cwd().realpath) bridged to libc via std.c.*. Stripping libc back out is tracked as F146.

Temporarily disabled (Phase 7 follow-ups)

The 0.16 stdlib reshapes were large enough that four features were collapsed to runtime-error stubs to land the migration cleanly. Each prints a clear error pointing at the F## item, and the original code is preserved in source or git history.

F##	Feature	Reason
F140	cljw.http/run-server	std.net.{Server,Stream} removed; needs std.Io.net rewrite
F141	cljw.http/get|post|put|delete	std.http.Client now requires .io field
F142	--nrepl-server (nREPL)	Same std.Io.net work + std.posix.poll replacement
F143	Raw-mode line editor	runRepl falls through to runReplSimple (functional)
F144	cljw build self-bundling	Needs std.fs.selfExePath replacement
F145	OrbStack Ubuntu re-validation	--seed 0 workaround needs re-test on 0.16
F146	Strip link_libc = true	After std.c.* shims have pure-Zig replacements

Full list in .dev/checklist.md.

See also

• Migration narrative: .dev/decisions.md D111
• Full CHANGELOG: CHANGELOG.md

v0.4.0

Full Changelog: v0.3.0...v0.4.0

Full Changelog: v0.3.0...v0.4.0

v0.3.0

Full Changelog: v0.2.0...v0.3.0

v0.2.0

Full Changelog: v0.1.0...v0.2.0

Full Changelog: v0.1.0...v0.2.0

v0.1.0

Full Changelog: https://github.com/clojurewasm/ClojureWasm/commits/v0.1.0