Node refuses to start when NODE_OPTIONS contains --expose-gc:
node: --expose-gc is not allowed in NODE_OPTIONS
NODE_OPTIONS is restricted to a small allowlist of flags that are safe
to inject via env (since any process able to set env vars on a node
child could otherwise enable arbitrary capabilities). --expose-gc is
not on that list and never has been -- it must be passed as a direct
CLI flag.
_launch_tui() was appending --expose-gc to NODE_OPTIONS before spawning
the TUI's node process, which made `hermes --tui` fail to start on
every modern node release. The intent (manual GC for long sessions to
avoid fatal-OOM) is preserved by inserting --expose-gc directly into
the node argv in _make_tui_argv() -- same effect, but actually allowed.
--max-old-space-size=8192 stays in NODE_OPTIONS: it *is* allowlisted,
and keeping it there means downstream node spawns inherit the same
heap cap without having to re-thread the flag through every spawn site.
The dev paths (`tsx src/entry.tsx` and `npm start` fallback) are left
alone -- they don't accept node flags directly, and the production
dist path is the one users actually hit via `hermes --tui`.
Repro before fix:
$ hermes --tui
/usr/bin/node: --expose-gc is not allowed in NODE_OPTIONS
2ea7cf287e