emulator throwing error MODULE_NOT_FOUND with --inspect-functions #2380

[REQUIRED] Environment info

firebase-tools: 8.4.3

Platform: mac os catalina 10.15.5
node -v
v12.18.1

visual studio code Version: 1.46.1

[REQUIRED] Test case

1. created new project with 1 firebase function "hello_word"

2. when I have run "firebase emulators:start --only firestore,functions"
   al works perfect

3. when I run "firebase emulators:start --only firestore,functions --inspect-functions"
   I've got error:

functions: Watching "/Users/username/Documents/Firebase/myproject/purchases/functions" for Cloud Functions...

internal/modules/cjs/loader.js:983
throw err;
^

Error: Cannot find module '/Users/username/Documents/Firebase/myproject/purchases/functions/--inspect=localhost:9229'
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:980:15)
at Function.Module._resolveFilename (pkg/prelude/bootstrap.js:1346:46)
at Function.Module._load (internal/modules/cjs/loader.js:862:27)
at Function.Module.runMain (pkg/prelude/bootstrap.js:1375:12)
at internal/main/run_main_module.js:18:47 {
code: 'MODULE_NOT_FOUND',
requireStack: []
}

[REQUIRED] Steps to reproduce

run "firebase emulators:start --only firestore,functions --inspect-functions"

firebase-debug-without-inspect.log

firebase-debug-with-inspect.log