Devtools uses invalid bun --json arg

[vincentparrett]

emitOutdatedDeps() runs bun outdated --json

Bun ignores --json and prints an ASCII table:

So tryParseJson returns null, and the exec callback hits a bare return — resolving nothing:

if (stdout) {
  const newOutdatedDeps = tryParseJson(stdout)
  if (!newOutdatedDeps) return        // ← promise never settles
  resolve(newOutdatedDeps)
}

That promise is awaited in the plugin's "mounted" handler, so the devtools panel's mount handler hangs forever.

I have no idea how to fix this - there are several issues on the bun repo about json output which have no real activity attached.

I would have created an issue for this but it wants a sandbox example - which seems pointless to me when the problem affects every project that uses one of the devtools plugins (I am using the vite-devtools plugin) with bun.

[sueun-dev]

Yeah, this repros on bun 1.3.14. bun outdated --json ignores the flag and prints the ASCII table, so tryParseJson returns null and emitOutdatedDeps hits the bare return without ever calling resolve. The mounted handler in devtools-vite does await outdatedDeps, so it hangs there and the package-json-read emit right after it doesn't run.

The empty-stdout branch (if (stdout)) has the same flaw, it doesn't settle. Fix is to settle instead of bailing: resolve(null) on both the parse-fail and no-stdout paths. The promise is already typed OutdatedDeps | null and the panel consumers do outdatedDeps || {}, so null just degrades to no data.

Checked the mechanism locally by feeding the real table output through that promise (hangs) vs a valid-JSON string (resolves fine). The bun flag is genuinely broken, but the freeze is fixable devtools-side.

[vincentparrett]

I have been experiencing a random hang with the vite dev server with bun on a tanstack start project - I found this issue whilst trying to figure out why it didn't start sometimes. I will say, since I commented out the devtools plugin I haven't seen the hang - it's only been a few hours but I have restarted many times today - I usually see it quite often (like every 2nd or 3rd attempt to restart the dev server). I can't say definatively that devtools is the cause but it's looking that way.