BUN_OPTIONS=--inspect uses same port if you spawn Bun from Bun script

[vjpr]

--------------------- Bun Inspector ---------------------
Listening:
  ws://localhost:6499/60kw9ocsez9
Inspect in browser:
  https://debug.bun.sh/#localhost:6499/60kw9ocsez9
--------------------- Bun Inspector ---------------------
--------------------- Bun Inspector ---------------------
Listening:
  ws://localhost:6499/c0d5jv7me9
Inspect in browser:
  https://debug.bun.sh/#localhost:6499/c0d5jv7me9
--------------------- Bun Inspector ---------------------


error: Failed to start server. Is port 6499 in use?

The inspector should choose next available port.

[tt-a1i]

This is a fair point. When spawning child Bun processes, the inspector should auto-increment ports.

Current workaround:

# Parent process
BUN_OPTIONS="--inspect=6499" bun parent.ts

# In parent.ts, spawn child with different port
Bun.spawn(["bun", "--inspect=6500", "child.ts"]);

Or dynamically:

const parentPort = 6499;
const childPort = parentPort + 1;

Bun.spawn(["bun", `--inspect=${childPort}`, "child.ts"], {
  env: {
    ...process.env,
    BUN_OPTIONS: `--inspect=${childPort}`,
  },
});

Better solution (feature request):
Bun could auto-detect port conflicts and increment, similar to how some dev servers find the next available port:

--------------------- Bun Inspector ---------------------
Port 6499 in use, using 6500 instead
Listening:
  ws://localhost:6500/xxx

Or support port 0 to auto-assign:

BUN_OPTIONS="--inspect=0" bun script.ts
# Outputs: Listening on ws://localhost:54321/xxx