[syrusakbary]

Summary

• terminate default-handled signals directly with the conventional 128 + signal status
• keep normal signal termination silent, matching POSIX/native process behavior
• add WASIX signal coverage for SA_SIGINFO, SA_RESETHAND, and default SIGTERM

Root cause

WASIX libc implemented every default terminating signal by calling abort(). That raises SIGABRT while the original signal is still being dispatched. A runtime that immediately delivers the nested signal can therefore re-enter the default signal path and repeatedly call abort(), producing an abort cascade instead of terminating once.

The terminating default action does not need the abort path or core-signal semantics. _Exit(128 + sig) terminates once and exposes the conventional shell status without writing diagnostics to stderr.

Verification

• built the complete wasm32 exnref/EH sysroot with ./build32-exnref-eh.sh
• exercised SA_SIGINFO, SA_RESETHAND, and default SIGTERM through the Wasmer JavaScript SDK: exit statuses 0, 138, and 143; no termination or abort diagnostics
• rebuilt Edge.js against the sysroot and ran 10 Next-style worker shutdown probes: all completed in 1–4 ms with no signal diagnostics
• ran a browser Next.js 16.3 production build through Edge.js, including Collecting build traces, verified .next/BUILD_ID, and served the production preview successfully

[Arshia001]

Tests for wasix-libc fixes and new features are added in the Wasmer repo, under wasix/tests/wasm_tests. Otherwise LGTM.