auto-optimize variant fastify: request properties lost across function-call boundary (request.headers undefined in helper functions)

[proggeramlug]

Symptom

A fastify route handler that passes the request object into a plain helper function gets request.headers === undefined inside the helper → TypeError: Cannot read properties of undefined (reading 'authorization') → fastify 500. The same property read inline in the handler body works.

Only in auto-optimize variant builds. The same source compiled against the prebuilt release libs behaves correctly.

Hit in production on hub.perryts.com: the two headless job endpoints (GET /api/v1/jobs/:id/{status,artifact}) 500'd on every request once the hub started being built by the worker pipeline (which compiles in docker with a Rust toolchain mounted → auto-optimize active). Worked around in PerryTS/hub@57b1ae5 by passing the header string instead of the request object.

Minimal repro (perry 0.5.1159, linux x86_64, /opt/perry-src exactly at the v0.5.1159 tag — no source/binary drift)

import Fastify from 'fastify';

const app = Fastify({ logger: false });

function authOf(request: any): string {
  return String(request.headers['authorization'] || 'none');
}

app.get('/direct', async (request: any, reply: any) => {
  reply.header('Content-Type', 'application/json');
  return JSON.stringify({ auth: String(request.headers['authorization'] || 'none') });
});

app.get('/helper', async (request: any, reply: any) => {
  reply.header('Content-Type', 'application/json');
  return JSON.stringify({ auth: authOf(request) });
});

app.listen({ port: 14470, host: '0.0.0.0' }, (err: any, address: string) => {
  if (err) { console.error('listen failed', err); process.exit(1); }
  console.log('repro up on 14470');
});

Prebuilt mode (no cargo on PATH → links released libs), perry compile src/main.ts -o repro --no-cache, 23.4 MB binary:

direct: {"auth":"Bearer abc"}
helper: {"auth":"Bearer abc"}     ← correct

Auto-optimize mode (cargo on PATH; perry logs auto-optimize: built .../perry-auto-51ee6998df3db294/release/libperry_runtime.a / libperry_stdlib.a / libperry_ext_fastify.a), same command, 12.1 MB binary:

direct: {"auth":"Bearer abc"}     ← inline read still correct
helper: {"statusCode":500,"error":"Internal Server Error","message":"Cannot read properties of undefined (reading 'authorization')"}

Same source, same perry binary, same machine — the only variable is the auto-optimize variant rebuild.

Notes

• Repro environment preserved on the linux worker at /tmp/perry-fastify-repro (binaries repro-prebuilt + repro-auto and the variant cache perry-auto-51ee6998df3db294).
• Looks like the variant feature-pruning (or the variant fastify ext's HIR interface) drops whatever keeps the native request object's property map reachable when the reference escapes the handler scope into a user function. Module-scope reads and handler-scope reads survive; a function parameter does not.
• macOS host builds of the same source did not reproduce (variant set may differ there).
• Possibly related precedent: the version-keyed perry-auto cache work in fix(compile): version-key the auto-optimize runtime cache (#4876) #5013 — this is NOT drift though; source and binary match exactly.