fetch linker error on macOS ARM64 with perry-react — _js_fetch_with_options not found

[tomkennedy22]

Howdy, opening a second issue of the night - which I think is distinct from #4

Saw in #3 that fetch is supposed to work natively without --enable-js-runtime. Tried it on macOS ARM64 using perry-react and got a linker error instead:

useEffect(() => {
  fetch("https://wttr.in/Chicago?format=3")
    .then(res => res.text())
    .then(text => setData(text))
}, [])

Undefined symbols for architecture arm64:
  "_js_fetch_with_options", referenced from:
      ___closure_1 in react_test_src_main_tsx.o
ld: symbol(s) not found for architecture arm64
Error: Linking failed

Seems like _js_fetch_with_options isn't making it into the linked binary on macOS. Could be a perry-react specific issue since the native stdlib isn't getting pulled in the same way. macOS ARM64, built from source.

[proggeramlug]

Hey Thomas, second fix of the night for you!

Root cause: fetch() is a global built-in (no import needed), but the symbol js_fetch_with_options is defined only in perry-stdlib. The needs_stdlib linker flag was only set based on explicit module imports (like import ... from "mysql2"), so projects that only used fetch() without any stdlib imports got linked with runtime-only — missing the symbol.

Fix: Added a uses_fetch flag to the HIR Module, set during lowering when fetch() / fetchWithAuth() / fetchPostWithAuth() calls are encountered, and checked in the linker to ensure stdlib is included.

Fixed in the same commit: b521064.