native: detect libc via process.report, not ldd

[Jeff Lubetkin (jefflub-ashby)]

Problem

isMusl() shells out to ldd --version and treats any failure as musl:

try {
  const ldd = execSync("ldd --version 2>&1", ...);
  return ldd.includes("musl");
} catch {
  return true; // <-- assumes musl on failure
}

Minimal runtime images (Google distroless, scratch) ship no ldd binary, so the execSync throws → the loader concludes musl on a glibc host → it builds platformKey = "linux-x64-musl", for which no prebuild/platform package exists, and fails at startup:

Native addon not found for linux-x64-musl. Install
@ashbyhq/libpg-query-native-linux-x64-musl or ensure it's in your dependencies.

This bit a real deploy onto gcr.io/distroless/nodejs24-debian13 (glibc, glibcVersionRuntime: 2.41) — the correct linux-x64 binary was present but never selected.

Fix

Detect libc using Node's own process.report.header.glibcVersionRuntime (set on glibc, absent on musl) — no subprocess, so it works in minimal images. Falls back to probing /lib/ld-musl-* on older runtimes without process.report, and defaults to glibc (the common case) when uncertain.

Verification

• gcr.io/distroless/nodejs24-debian13:nonroot (glibc): isMusl() → false; loader selects linux-x64 and parses (version: 180004). ✅
• node:24-alpine (musl): isMusl() → true. ✅

Bumps the package to 0.1.1.

🤖 Generated with Claude Code