Firebase emulator suite startup painfully slow when WSL2 networking mode is `mirrored`

[REQUIRED] Environment info

firebase-tools: 13.20.2

Platform: WSL with Ubuntu 22.04.4 LTS (Running under Windows 23H2 22631.4169)

[REQUIRED] Test case

.firebaserc

{
    "projects": {
        "default": "demo-test"
    }
}

firebase.json

{
  "emulators": {
    "firestore": {
      "port": 1234
    },
    "auth": {
      "port": 1235
    },
    "database": {
      "port": 1236
    },
    "ui": {
      "enabled": true
    }
  }
}

[REQUIRED] Steps to reproduce

Set up .wslconfig file with the below content:
```
[wsl2]
networkingMode=mirrored
```
Shutdown WSL via wsl --shutdown, wait for 8-10 seconds and start it again
Start emulator suite using `firebase emulators:start --debug

[REQUIRED] Expected behavior

Emulator suite should start up relatively quickly.

[REQUIRED] Actual behavior

Emulator suite seems to "hang" at the last few steps, and delays the startup. (2 minute interval between the last two log entries can be seen)

❯ firebase emulators:start --debug
[2024-10-01T12:44:52.214Z] > command requires scopes: ["email","openid","https://www.googleapis.com/auth/cloudplatformprojects.readonly","https://www.googleapis.com/auth/firebase","https://www.googleapis.com/auth/cloud-platform"]
[2024-10-01T12:44:52.214Z] > authorizing via signed-in user (abc@xyz.com)
[2024-10-01T12:44:52.390Z] openjdk version "11.0.20.1" 2023-08-24

[2024-10-01T12:44:52.390Z] OpenJDK Runtime Environment Temurin-11.0.20.1+1 (build 11.0.20.1+1)
OpenJDK 64-Bit Server VM Temurin-11.0.20.1+1 (build 11.0.20.1+1, mixed mode)

[2024-10-01T12:44:52.395Z] Parsed Java major version: 11
i  emulators: Starting emulators: auth, firestore, database {"metadata":{"emulator":{"name":"hub"},"message":"Starting emulators: auth, firestore, database"}}
i  emulators: Detected demo project ID "demo-test", emulated services will use a demo configuration and attempts to access non-emulated services for this project will fail. {"metadata":{"emulator":{"name":"hub"},"message":"Detected demo project ID \"demo-test\", emulated services will use a demo configuration and attempts to access non-emulated services for this project will fail."}}
[2024-10-01T12:44:52.465Z] assigned listening specs for emulators {"user":{"hub":[{"address":"127.0.0.1","family":"IPv4","port":4400}],"ui":[{"address":"127.0.0.1","family":"IPv4","port":4000}],"logging":[{"address":"127.0.0.1","family":"IPv4","port":4500}],"auth":[{"address":"127.0.0.1","family":"IPv4","port":1235}],"firestore":[{"address":"127.0.0.1","family":"IPv4","port":1234}],"firestore.websocket":[{"address":"127.0.0.1","family":"IPv4","port":9150}],"database":[{"address":"127.0.0.1","family":"IPv4","port":1236}]},"metadata":{"message":"assigned listening specs for emulators"}}
[2024-10-01T12:44:52.467Z] [hub] writing locator at /tmp/hub-demo-test.json
⚠  firestore: Cloud Firestore Emulator does not support multiple databases yet. {"metadata":{"emulator":{"name":"firestore"},"message":"Cloud Firestore Emulator does not support multiple databases yet."}}
⚠  firestore: Did not find a Cloud Firestore rules file specified in a firebase.json config file. {"metadata":{"emulator":{"name":"firestore"},"message":"Did not find a Cloud Firestore rules file specified in a firebase.json config file."}}
⚠  firestore: The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration. {"metadata":{"emulator":{"name":"firestore"},"message":"The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration."}}
[2024-10-01T12:44:52.479Z] Ignoring unsupported arg: auto_download {"metadata":{"emulator":{"name":"firestore"},"message":"Ignoring unsupported arg: auto_download"}}
[2024-10-01T12:44:52.479Z] Ignoring unsupported arg: single_project_mode_error {"metadata":{"emulator":{"name":"firestore"},"message":"Ignoring unsupported arg: single_project_mode_error"}}
[2024-10-01T12:44:52.479Z] Starting Firestore Emulator with command {"binary":"java","args":["-Djava.net.preferIPv4Stack=true","-Dgoogle.cloud_firestore.debug_log_level=FINE","-Duser.language=en","-jar","/home/sagar/.cache/firebase/emulators/cloud-firestore-emulator-v1.19.8.jar","--host","127.0.0.1","--port",1234,"--websocket_port",9150,"--project_id","demo-test","--single_project_mode",true],"optionalArgs":["port","webchannel_port","host","rules","websocket_port","functions_emulator","seed_from_export","project_id","single_project_mode"],"joinArgs":false,"shell":false,"port":1234} {"metadata":{"emulator":{"name":"firestore"},"message":"Starting Firestore Emulator with command {\"binary\":\"java\",\"args\":[\"-Djava.net.preferIPv4Stack=true\",\"-Dgoogle.cloud_firestore.debug_log_level=FINE\",\"-Duser.language=en\",\"-jar\",\"/home/sagar/.cache/firebase/emulators/cloud-firestore-emulator-v1.19.8.jar\",\"--host\",\"127.0.0.1\",\"--port\",1234,\"--websocket_port\",9150,\"--project_id\",\"demo-test\",\"--single_project_mode\",true],\"optionalArgs\":[\"port\",\"webchannel_port\",\"host\",\"rules\",\"websocket_port\",\"functions_emulator\",\"seed_from_export\",\"project_id\",\"single_project_mode\"],\"joinArgs\":false,\"shell\":false,\"port\":1234}"}}
i  firestore: Firestore Emulator logging to firestore-debug.log {"metadata":{"emulator":{"name":"firestore"},"message":"Firestore Emulator logging to \u001b[1mfirestore-debug.log\u001b[22m"}}
[2024-10-01T12:44:53.756Z] Oct 01, 2024 6:14:53 PM com.google.cloud.datastore.emulator.firestore.websocket.WebSocketServer start
INFO: Started WebSocket server on ws://127.0.0.1:9150
 {"metadata":{"emulator":{"name":"firestore"},"message":"Oct 01, 2024 6:14:53 PM com.google.cloud.datastore.emulator.firestore.websocket.WebSocketServer start\nINFO: Started WebSocket server on ws://127.0.0.1:9150\n"}}
[2024-10-01T12:44:53.873Z] API endpoint: http:// {"metadata":{"emulator":{"name":"firestore"},"message":"API endpoint: http://"}}
[2024-10-01T12:44:53.874Z] 127.0.0.1:1234
If you are using a library that supports the FIRESTORE_EMULATOR_HOST environment variable, run:

   export FIRESTORE_EMULATOR_HOST=127.0.0.1:1234

If you are running a Firestore in Datastore Mode project, run:

   export DATASTORE_EMULATOR_HOST=127.0.0.1:1234

Note: Support for Datastore Mode is in preview. If you encounter any bugs please file at https://github.com/firebase/firebase-tools/issues.
Dev App Server is now running.

 {"metadata":{"emulator":{"name":"firestore"},"message":"127.0.0.1:1234\nIf you are using a library that supports the FIRESTORE_EMULATOR_HOST environment variable, run:\n\n   export FIRESTORE_EMULATOR_HOST=127.0.0.1:1234\n\nIf you are running a Firestore in Datastore Mode project, run:\n\n   export DATASTORE_EMULATOR_HOST=127.0.0.1:1234\n\nNote: Support for Datastore Mode is in preview. If you encounter any bugs please file at https://github.com/firebase/firebase-tools/issues.\nDev App Server is now running.\n\n"}}
✔  firestore: Firestore Emulator UI websocket is running on 9150. {"metadata":{"emulator":{"name":"firestore"},"message":"Firestore Emulator UI websocket is running on 9150."}}
[2024-10-01T12:44:53.891Z] Checked if tokens are valid: false, expires at: 1663155116253
[2024-10-01T12:44:53.891Z] Checked if tokens are valid: false, expires at: 1663155116253
[2024-10-01T12:44:53.891Z] > refreshing access token with scopes: []
[2024-10-01T12:44:53.893Z] >>> [apiv2][query] POST https://www.googleapis.com/oauth2/v3/token [none]
[2024-10-01T12:44:53.893Z] >>> [apiv2][body] POST https://www.googleapis.com/oauth2/v3/token [omitted]
[2024-10-01T12:44:54.130Z] <<< [apiv2][status] POST https://www.googleapis.com/oauth2/v3/token 400
[2024-10-01T12:44:54.131Z] <<< [apiv2][body] POST https://www.googleapis.com/oauth2/v3/token [omitted]
[2024-10-01T12:44:54.131Z] >>> [apiv2][query] GET https://firebase.googleapis.com/v1beta1/projects/demo-test [none]
[2024-10-01T12:44:54.368Z] <<< [apiv2][status] GET https://firebase.googleapis.com/v1beta1/projects/demo-test 401
[2024-10-01T12:44:54.368Z] <<< [apiv2][body] GET https://firebase.googleapis.com/v1beta1/projects/demo-test {"error":{"code":401,"message":"Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.","status":"UNAUTHENTICATED"}}
[2024-10-01T12:44:54.368Z] Got a 401 Unauthenticated error for a call that required authentication. Refreshing tokens.
[2024-10-01T12:44:54.368Z] Checked if tokens are valid: false, expires at: 1663155116253
[2024-10-01T12:44:54.368Z] Checked if tokens are valid: false, expires at: 1663155116253
[2024-10-01T12:44:54.368Z] > refreshing access token with scopes: []
[2024-10-01T12:44:54.369Z] >>> [apiv2][query] POST https://www.googleapis.com/oauth2/v3/token [none]
[2024-10-01T12:44:54.369Z] >>> [apiv2][body] POST https://www.googleapis.com/oauth2/v3/token [omitted]
[2024-10-01T12:44:54.459Z] <<< [apiv2][status] POST https://www.googleapis.com/oauth2/v3/token 400
[2024-10-01T12:44:54.459Z] <<< [apiv2][body] POST https://www.googleapis.com/oauth2/v3/token [omitted]
[2024-10-01T12:44:54.459Z] HTTP Error: 401, Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.
[2024-10-01T12:44:54.459Z] Failed to retrieve default database instance: {"name":"FirebaseError","children":[],"exit":2,"message":"Failed to get Firebase project demo-test. Please make sure the project exists and your account has permission to access it.","original":{"name":"FirebaseError","children":[],"context":{"body":{"error":{"code":401,"message":"Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.","status":"UNAUTHENTICATED"}},"response":{"statusCode":401}},"exit":1,"message":"HTTP Error: 401, Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.","status":401},"status":500} {"metadata":{"emulator":{"name":"database"},"message":"Failed to retrieve default database instance: {\"name\":\"FirebaseError\",\"children\":[],\"exit\":2,\"message\":\"Failed to get Firebase project demo-test. Please make sure the project exists and your account has permission to access it.\",\"original\":{\"name\":\"FirebaseError\",\"children\":[],\"context\":{\"body\":{\"error\":{\"code\":401,\"message\":\"Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.\",\"status\":\"UNAUTHENTICATED\"}},\"response\":{\"statusCode\":401}},\"exit\":1,\"message\":\"HTTP Error: 401, Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.\",\"status\":401},\"status\":500}"}}
[2024-10-01T12:44:54.459Z] database rules config:  []
⚠  database: Did not find a Realtime Database rules file specified in a firebase.json config file. The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration. {"metadata":{"emulator":{"name":"database"},"message":"Did not find a Realtime Database rules file specified in a firebase.json config file. The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration."}}
[2024-10-01T12:44:54.460Z] Ignoring unsupported arg: projectId {"metadata":{"emulator":{"name":"database"},"message":"Ignoring unsupported arg: projectId"}}
[2024-10-01T12:44:54.460Z] Ignoring unsupported arg: auto_download {"metadata":{"emulator":{"name":"database"},"message":"Ignoring unsupported arg: auto_download"}}
[2024-10-01T12:44:54.460Z] Ignoring unsupported arg: rules {"metadata":{"emulator":{"name":"database"},"message":"Ignoring unsupported arg: rules"}}
[2024-10-01T12:44:54.460Z] Starting Database Emulator with command {"binary":"java","args":["-Djava.net.preferIPv4Stack=true","-Duser.language=en","-jar","/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar","--host","127.0.0.1","--port",1236,"--single_project_mode","Warning"],"optionalArgs":["port","host","functions_emulator_port","functions_emulator_host","single_project_mode"],"joinArgs":false,"shell":false,"port":1236} {"metadata":{"emulator":{"name":"database"},"message":"Starting Database Emulator with command {\"binary\":\"java\",\"args\":[\"-Djava.net.preferIPv4Stack=true\",\"-Duser.language=en\",\"-jar\",\"/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar\",\"--host\",\"127.0.0.1\",\"--port\",1236,\"--single_project_mode\",\"Warning\"],\"optionalArgs\":[\"port\",\"host\",\"functions_emulator_port\",\"functions_emulator_host\",\"single_project_mode\"],\"joinArgs\":false,\"shell\":false,\"port\":1236}"}}
i  database: Database Emulator logging to database-debug.log {"metadata":{"emulator":{"name":"database"},"message":"Database Emulator logging to \u001b[1mdatabase-debug.log\u001b[22m"}}
[2024-10-01T12:44:55.131Z] WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by io.netty.util.internal.ReflectionUtil (file:/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar) to field sun.nio.ch.SelectorImpl.selectedKeys
WARNING: Please consider reporting this to the maintainers of io.netty.util.internal.ReflectionUtil
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
 {"metadata":{"emulator":{"name":"database"},"message":"WARNING: An illegal reflective access operation has occurred\nWARNING: Illegal reflective access by io.netty.util.internal.ReflectionUtil (file:/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar) to field sun.nio.ch.SelectorImpl.selectedKeys\nWARNING: Please consider reporting this to the maintainers of io.netty.util.internal.ReflectionUtil\nWARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations\nWARNING: All illegal access operations will be denied in a future release\n"}}
[2024-10-01T12:44:55.685Z] 18:14:55.684 [NamespaceSystem-akka.actor.default-dispatcher-4] INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started
 {"metadata":{"emulator":{"name":"database"},"message":"18:14:55.684 [NamespaceSystem-akka.actor.default-dispatcher-4] INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started\n"}}
[2024-10-01T12:44:55.837Z] 18:14:55.836 [main] INFO com.firebase.server.forge.App$ - Listening at 127.0.0.1:1236
 {"metadata":{"emulator":{"name":"database"},"message":"18:14:55.836 [main] INFO com.firebase.server.forge.App$ - Listening at 127.0.0.1:1236\n"}}
[2024-10-01T12:45:00.480Z] Ignoring unsupported arg: auto_download {"metadata":{"emulator":{"name":"ui"},"message":"Ignoring unsupported arg: auto_download"}}
[2024-10-01T12:45:00.480Z] Ignoring unsupported arg: port {"metadata":{"emulator":{"name":"ui"},"message":"Ignoring unsupported arg: port"}}
[2024-10-01T12:45:00.480Z] Starting Emulator UI with command {"binary":"node","args":["/home/sagar/.cache/firebase/emulators/ui-v1.13.0/server/server.mjs"],"optionalArgs":[],"joinArgs":false,"shell":false,"port":4000} {"metadata":{"emulator":{"name":"ui"},"message":"Starting Emulator UI with command {\"binary\":\"node\",\"args\":[\"/home/sagar/.cache/firebase/emulators/ui-v1.13.0/server/server.mjs\"],\"optionalArgs\":[],\"joinArgs\":false,\"shell\":false,\"port\":4000}"}}
i  ui: Emulator UI logging to ui-debug.log {"metadata":{"emulator":{"name":"ui"},"message":"Emulator UI logging to \u001b[1mui-debug.log\u001b[22m"}}
[2024-10-01T12:45:00.565Z] Web / API server started at 127.0.0.1:4000
 {"metadata":{"emulator":{"name":"ui"},"message":"Web / API server started at 127.0.0.1:4000\n"}}
[2024-10-01T12:47:14.408Z] Could not find VSCode notification endpoint: FetchError: request to http://localhost:40001/vscode/notify failed, reason: connect ETIMEDOUT 127.0.0.1:40001

┌─────────────────────────────────────────────────────────────┐
│ ✔  All emulators ready! It is now safe to connect your app. │
│ i  View Emulator UI at http://127.0.0.1:4000/               │
└─────────────────────────────────────────────────────────────┘

┌────────────────┬────────────────┬─────────────────────────────────┐
│ Emulator       │ Host:Port      │ View in Emulator UI             │
├────────────────┼────────────────┼─────────────────────────────────┤
│ Authentication │ 127.0.0.1:1235 │ http://127.0.0.1:4000/auth      │
├────────────────┼────────────────┼─────────────────────────────────┤
│ Firestore      │ 127.0.0.1:1234 │ http://127.0.0.1:4000/firestore │
├────────────────┼────────────────┼─────────────────────────────────┤
│ Database       │ 127.0.0.1:1236 │ http://127.0.0.1:4000/database  │
└────────────────┴────────────────┴─────────────────────────────────┘
  Emulator Hub running at 127.0.0.1:4400
  Other reserved ports: 4500, 9150

Issues? Report them at https://github.com/firebase/firebase-tools/issues and attach the *-debug.log files.

Hi @aalej!

I have not used the Data Connect emulator.

Downgrading to 13.18.0 seems to have worked, the emulator starts up quickly again.

❯ firebase emulators:start --debug
[2024-10-01T21:43:38.128Z] > command requires scopes: ["email","openid","https://www.googleapis.com/auth/cloudplatformprojects.readonly","https://www.googleapis.com/auth/firebase","https://www.googleapis.com/auth/cloud-platform"]
[2024-10-01T21:43:38.129Z] > authorizing via signed-in user (abc@xyz.com)
[2024-10-01T21:43:38.250Z] openjdk version "11.0.20.1" 2023-08-24

[2024-10-01T21:43:38.250Z] OpenJDK Runtime Environment Temurin-11.0.20.1+1 (build 11.0.20.1+1)
OpenJDK 64-Bit Server VM Temurin-11.0.20.1+1 (build 11.0.20.1+1, mixed mode)

[2024-10-01T21:43:38.254Z] Parsed Java major version: 11
i  emulators: Starting emulators: auth, firestore, database {"metadata":{"emulator":{"name":"hub"},"message":"Starting emulators: auth, firestore, database"}}
i  emulators: Detected demo project ID "demo-test", emulated services will use a demo configuration and attempts to access non-emulated services for this project will fail. {"metadata":{"emulator":{"name":"hub"},"message":"Detected demo project ID \"demo-test\", emulated services will use a demo configuration and attempts to access non-emulated services for this project will fail."}}
[2024-10-01T21:43:38.316Z] assigned listening specs for emulators {"user":{"hub":[{"address":"127.0.0.1","family":"IPv4","port":4400}],"ui":[{"address":"127.0.0.1","family":"IPv4","port":4000}],"logging":[{"address":"127.0.0.1","family":"IPv4","port":4500}],"auth":[{"address":"127.0.0.1","family":"IPv4","port":1235}],"firestore":[{"address":"127.0.0.1","family":"IPv4","port":1234}],"firestore.websocket":[{"address":"127.0.0.1","family":"IPv4","port":9150}],"database":[{"address":"127.0.0.1","family":"IPv4","port":1236}]},"metadata":{"message":"assigned listening specs for emulators"}}
[2024-10-01T21:43:38.319Z] [hub] writing locator at /tmp/hub-demo-test.json
⚠  firestore: Cloud Firestore Emulator does not support multiple databases yet. {"metadata":{"emulator":{"name":"firestore"},"message":"Cloud Firestore Emulator does not support multiple databases yet."}}
⚠  firestore: Did not find a Cloud Firestore rules file specified in a firebase.json config file. {"metadata":{"emulator":{"name":"firestore"},"message":"Did not find a Cloud Firestore rules file specified in a firebase.json config file."}}
⚠  firestore: The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration. {"metadata":{"emulator":{"name":"firestore"},"message":"The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration."}}
[2024-10-01T21:43:38.330Z] Ignoring unsupported arg: auto_download {"metadata":{"emulator":{"name":"firestore"},"message":"Ignoring unsupported arg: auto_download"}}
[2024-10-01T21:43:38.330Z] Ignoring unsupported arg: single_project_mode_error {"metadata":{"emulator":{"name":"firestore"},"message":"Ignoring unsupported arg: single_project_mode_error"}}
[2024-10-01T21:43:38.330Z] Starting Firestore Emulator with command {"binary":"java","args":["-Djava.net.preferIPv4Stack=true","-Dgoogle.cloud_firestore.debug_log_level=FINE","-Duser.language=en","-jar","/home/sagar/.cache/firebase/emulators/cloud-firestore-emulator-v1.19.8.jar","--host","127.0.0.1","--port",1234,"--websocket_port",9150,"--project_id","demo-test","--single_project_mode",true],"optionalArgs":["port","webchannel_port","host","rules","websocket_port","functions_emulator","seed_from_export","project_id","single_project_mode"],"joinArgs":false,"shell":false} {"metadata":{"emulator":{"name":"firestore"},"message":"Starting Firestore Emulator with command {\"binary\":\"java\",\"args\":[\"-Djava.net.preferIPv4Stack=true\",\"-Dgoogle.cloud_firestore.debug_log_level=FINE\",\"-Duser.language=en\",\"-jar\",\"/home/sagar/.cache/firebase/emulators/cloud-firestore-emulator-v1.19.8.jar\",\"--host\",\"127.0.0.1\",\"--port\",1234,\"--websocket_port\",9150,\"--project_id\",\"demo-test\",\"--single_project_mode\",true],\"optionalArgs\":[\"port\",\"webchannel_port\",\"host\",\"rules\",\"websocket_port\",\"functions_emulator\",\"seed_from_export\",\"project_id\",\"single_project_mode\"],\"joinArgs\":false,\"shell\":false}"}}
i  firestore: Firestore Emulator logging to firestore-debug.log {"metadata":{"emulator":{"name":"firestore"},"message":"Firestore Emulator logging to \u001b[1mfirestore-debug.log\u001b[22m"}}
[2024-10-01T21:43:39.345Z] Oct 02, 2024 3:13:39 AM com.google.cloud.datastore.emulator.firestore.websocket.WebSocketServer start
INFO: Started WebSocket server on ws://127.0.0.1:9150
 {"metadata":{"emulator":{"name":"firestore"},"message":"Oct 02, 2024 3:13:39 AM com.google.cloud.datastore.emulator.firestore.websocket.WebSocketServer start\nINFO: Started WebSocket server on ws://127.0.0.1:9150\n"}}
[2024-10-01T21:43:39.461Z] API endpoint: http:// {"metadata":{"emulator":{"name":"firestore"},"message":"API endpoint: http://"}}
[2024-10-01T21:43:39.461Z] 127.0.0.1:1234
If you are using a library that supports the FIRESTORE_EMULATOR_HOST environment variable, run:

   export FIRESTORE_EMULATOR_HOST=127.0.0.1:1234

If you are running a Firestore in Datastore Mode project, run:

   export DATASTORE_EMULATOR_HOST=127.0.0.1:1234

Note: Support for Datastore Mode is in preview. If you encounter any bugs please file at https://github.com/firebase/firebase-tools/issues.
Dev App Server is now running.

 {"metadata":{"emulator":{"name":"firestore"},"message":"127.0.0.1:1234\nIf you are using a library that supports the FIRESTORE_EMULATOR_HOST environment variable, run:\n\n   export FIRESTORE_EMULATOR_HOST=127.0.0.1:1234\n\nIf you are running a Firestore in Datastore Mode project, run:\n\n   export DATASTORE_EMULATOR_HOST=127.0.0.1:1234\n\nNote: Support for Datastore Mode is in preview. If you encounter any bugs please file at https://github.com/firebase/firebase-tools/issues.\nDev App Server is now running.\n\n"}}
✔  firestore: Firestore Emulator UI websocket is running on 9150. {"metadata":{"emulator":{"name":"firestore"},"message":"Firestore Emulator UI websocket is running on 9150."}}
[2024-10-01T21:43:39.544Z] > refreshing access token with scopes: []
[2024-10-01T21:43:39.545Z] >>> [apiv2][query] POST https://www.googleapis.com/oauth2/v3/token [none]
[2024-10-01T21:43:39.546Z] >>> [apiv2][body] POST https://www.googleapis.com/oauth2/v3/token [omitted]
[2024-10-01T21:43:39.818Z] <<< [apiv2][status] POST https://www.googleapis.com/oauth2/v3/token 400
[2024-10-01T21:43:39.818Z] <<< [apiv2][body] POST https://www.googleapis.com/oauth2/v3/token [omitted]
[2024-10-01T21:43:39.818Z] >>> [apiv2][query] GET https://firebase.googleapis.com/v1beta1/projects/demo-test [none]
[2024-10-01T21:43:40.307Z] <<< [apiv2][status] GET https://firebase.googleapis.com/v1beta1/projects/demo-test 401
[2024-10-01T21:43:40.307Z] <<< [apiv2][body] GET https://firebase.googleapis.com/v1beta1/projects/demo-test {"error":{"code":401,"message":"Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.","status":"UNAUTHENTICATED"}}
[2024-10-01T21:43:40.308Z] HTTP Error: 401, Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.
[2024-10-01T21:43:40.308Z] Failed to retrieve default database instance: {"name":"FirebaseError","children":[],"exit":2,"message":"Failed to get Firebase project demo-test. Please make sure the project exists and your account has permission to access it.","original":{"name":"FirebaseError","children":[],"context":{"body":{"error":{"code":401,"message":"Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.","status":"UNAUTHENTICATED"}},"response":{"statusCode":401}},"exit":1,"message":"HTTP Error: 401, Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.","status":401},"status":500} {"metadata":{"emulator":{"name":"database"},"message":"Failed to retrieve default database instance: {\"name\":\"FirebaseError\",\"children\":[],\"exit\":2,\"message\":\"Failed to get Firebase project demo-test. Please make sure the project exists and your account has permission to access it.\",\"original\":{\"name\":\"FirebaseError\",\"children\":[],\"context\":{\"body\":{\"error\":{\"code\":401,\"message\":\"Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.\",\"status\":\"UNAUTHENTICATED\"}},\"response\":{\"statusCode\":401}},\"exit\":1,\"message\":\"HTTP Error: 401, Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.\",\"status\":401},\"status\":500}"}}
[2024-10-01T21:43:40.308Z] database rules config:  []
⚠  database: Did not find a Realtime Database rules file specified in a firebase.json config file. The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration. {"metadata":{"emulator":{"name":"database"},"message":"Did not find a Realtime Database rules file specified in a firebase.json config file. The emulator will default to allowing all reads and writes. Learn more about this option: https://firebase.google.com/docs/emulator-suite/install_and_configure#security_rules_configuration."}}
[2024-10-01T21:43:40.309Z] Ignoring unsupported arg: projectId {"metadata":{"emulator":{"name":"database"},"message":"Ignoring unsupported arg: projectId"}}
[2024-10-01T21:43:40.309Z] Ignoring unsupported arg: auto_download {"metadata":{"emulator":{"name":"database"},"message":"Ignoring unsupported arg: auto_download"}}
[2024-10-01T21:43:40.309Z] Ignoring unsupported arg: rules {"metadata":{"emulator":{"name":"database"},"message":"Ignoring unsupported arg: rules"}}
[2024-10-01T21:43:40.309Z] Starting Database Emulator with command {"binary":"java","args":["-Djava.net.preferIPv4Stack=true","-Duser.language=en","-jar","/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar","--host","127.0.0.1","--port",1236,"--single_project_mode","Warning"],"optionalArgs":["port","host","functions_emulator_port","functions_emulator_host","single_project_mode"],"joinArgs":false,"shell":false} {"metadata":{"emulator":{"name":"database"},"message":"Starting Database Emulator with command {\"binary\":\"java\",\"args\":[\"-Djava.net.preferIPv4Stack=true\",\"-Duser.language=en\",\"-jar\",\"/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar\",\"--host\",\"127.0.0.1\",\"--port\",1236,\"--single_project_mode\",\"Warning\"],\"optionalArgs\":[\"port\",\"host\",\"functions_emulator_port\",\"functions_emulator_host\",\"single_project_mode\"],\"joinArgs\":false,\"shell\":false}"}}
i  database: Database Emulator logging to database-debug.log {"metadata":{"emulator":{"name":"database"},"message":"Database Emulator logging to \u001b[1mdatabase-debug.log\u001b[22m"}}
[2024-10-01T21:43:40.894Z] WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by io.netty.util.internal.ReflectionUtil (file:/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar) to field sun.nio.ch.SelectorImpl.selectedKeys
WARNING: Please consider reporting this to the maintainers of io.netty.util.internal.ReflectionUtil
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
 {"metadata":{"emulator":{"name":"database"},"message":"WARNING: An illegal reflective access operation has occurred\nWARNING: Illegal reflective access by io.netty.util.internal.ReflectionUtil (file:/home/sagar/.cache/firebase/emulators/firebase-database-emulator-v4.11.2.jar) to field sun.nio.ch.SelectorImpl.selectedKeys\nWARNING: Please consider reporting this to the maintainers of io.netty.util.internal.ReflectionUtil\nWARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations\nWARNING: All illegal access operations will be denied in a future release\n"}}
[2024-10-01T21:43:41.376Z] 03:13:41.375 [NamespaceSystem-akka.actor.default-dispatcher-5] INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started
 {"metadata":{"emulator":{"name":"database"},"message":"03:13:41.375 [NamespaceSystem-akka.actor.default-dispatcher-5] INFO akka.event.slf4j.Slf4jLogger - Slf4jLogger started\n"}}
[2024-10-01T21:43:41.491Z] 03:13:41.490 [main] INFO com.firebase.server.forge.App$ - Listening at 127.0.0.1:1236
 {"metadata":{"emulator":{"name":"database"},"message":"03:13:41.490 [main] INFO com.firebase.server.forge.App$ - Listening at 127.0.0.1:1236\n"}}
[2024-10-01T21:43:46.360Z] Ignoring unsupported arg: auto_download {"metadata":{"emulator":{"name":"ui"},"message":"Ignoring unsupported arg: auto_download"}}
[2024-10-01T21:43:46.360Z] Ignoring unsupported arg: port {"metadata":{"emulator":{"name":"ui"},"message":"Ignoring unsupported arg: port"}}
[2024-10-01T21:43:46.360Z] Starting Emulator UI with command {"binary":"node","args":["/home/sagar/.cache/firebase/emulators/ui-v1.13.0/server/server.mjs"],"optionalArgs":[],"joinArgs":false,"shell":false} {"metadata":{"emulator":{"name":"ui"},"message":"Starting Emulator UI with command {\"binary\":\"node\",\"args\":[\"/home/sagar/.cache/firebase/emulators/ui-v1.13.0/server/server.mjs\"],\"optionalArgs\":[],\"joinArgs\":false,\"shell\":false}"}}
i  ui: Emulator UI logging to ui-debug.log {"metadata":{"emulator":{"name":"ui"},"message":"Emulator UI logging to \u001b[1mui-debug.log\u001b[22m"}}
[2024-10-01T21:43:46.445Z] Web / API server started at 127.0.0.1:4000
 {"metadata":{"emulator":{"name":"ui"},"message":"Web / API server started at 127.0.0.1:4000\n"}}

┌─────────────────────────────────────────────────────────────┐
│ ✔  All emulators ready! It is now safe to connect your app. │
│ i  View Emulator UI at http://127.0.0.1:4000/               │
└─────────────────────────────────────────────────────────────┘

┌────────────────┬────────────────┬─────────────────────────────────┐
│ Emulator       │ Host:Port      │ View in Emulator UI             │
├────────────────┼────────────────┼─────────────────────────────────┤
│ Authentication │ 127.0.0.1:1235 │ http://127.0.0.1:4000/auth      │
├────────────────┼────────────────┼─────────────────────────────────┤
│ Firestore      │ 127.0.0.1:1234 │ http://127.0.0.1:4000/firestore │
├────────────────┼────────────────┼─────────────────────────────────┤
│ Database       │ 127.0.0.1:1236 │ http://127.0.0.1:4000/database  │
└────────────────┴────────────────┴─────────────────────────────────┘
  Emulator Hub running at 127.0.0.1:4400
  Other reserved ports: 4500, 9150

Issues? Report them at https://github.com/firebase/firebase-tools/issues and attach the *-debug.log files.

For reference, this works just fine with 13.20.2 when I turn WSL2's networking mode back to nat. It also works fine in MacOS with 13.20.2.

firebase / firebase-tools