Two fixes for the intermittent wx-build failure on CI (zipstrm.cpp: fatal
error: 'zlib.h' file not found, surviving the serial retry):
- build-wx-wasm.sh: --with-zlib=sys resolves to the Emscripten zlib PORT,
which only `embuilder build zlib` installs — and that ran only in the
configure branch. A pre-configured build dir (CI cache) + fresh emsdk
therefore died on any recompile of a zlib-using TU. Ensure the port
before every make; --force because embuilder stamps the port on libz.a
alone, so a half-populated cache would no-op.
- wasm-build.yml: the cache-restore `touch {} +` stamped files ns-apart in
readdir order; GNU make 4.x compares ns mtimes, so objects touched before
a generated header they depend on (wx/setup.h, pcre2.h via .deps/*.d)
recompiled — a random subset per run, which is what made the failure
flaky. Use one shared timestamp instead: equal mtimes = up to date.
Reproduced + validated locally (remove sysroot zlib.h + one .o → exact CI
failure; with fix, self-heals in 0.5s; Linux make ns/equal-mtime behavior
verified in a container).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XeiSRRScdaox5jBueJNcyG
f49d536f95