Google App Engine - Error response 13 issue

Question

I'm trying to deploy an application on Google App Engine but running into an error that doesn't include much information as to why the error is occurring. Here is the last lines of the log file on a run of: gcloud app deploy --verbosity=debug:

DEBUG: Converted YAML to JSON: "{
  "automaticScaling": {
    "maxTotalInstances": 2,
    "minTotalInstances": 1
  },
  "betaSettings": {
    "module_yaml_path": "app.yaml",
    "vm_runtime": "ruby"
  },
  "entrypoint": {
    "shell": "bundle exec rails server Puma -p $PORT"
  },
  "env": "flex",
  "envVariables": {
    "RAILS_ENV": "production"
  },
  "handlers": [
    {
      "script": {
        "scriptPath": "PLACEHOLDER"
      },
      "urlRegex": ".*"
    }
  ],
  "runtime": "vm"
}"
Updating service [default] (this may take several minutes)...⠧DEBUG: Operation [apps/xxxxxxxx/operations/177ebe52-a136-403a-90e8-c71bc6cc94b9] not complete. Waiting to retry.       
Updating service [default] (this may take several minutes)...⠧DEBUG: Operation [apps/xxxxxxxx/operations/177ebe52-a136-403a-90e8-c71bc6cc94b9] complete. Result: {                   
    "done": true,
    "error": {
        "code": 13,
        "message": "An internal error occurred."
    },
    "metadata": {
        "@type": "type.googleapis.com/google.appengine.v1.OperationMetadataV1",
        "insertTime": "2022-04-25T16:39:42.625Z",
        "method": "google.appengine.v1.Versions.CreateVersion",
        "target": "apps/xxxxxxxx/services/default/versions/20220425t085403",
        "user": "xxxxxxxxxxxx"
    },
    "name": "apps/xxxxxxxx/operations/177ebe52-a136-403a-90e8-c71bc6cc94b9"
}
Updating service [default] (this may take several minutes)...failed.                                                                                                                             
DEBUG: (gcloud.app.deploy) Error Response: [13] An internal error occurred.
Traceback (most recent call last):
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/calliope/cli.py", line 987, in Execute
    resources = calliope_command.Run(cli=self, args=args)
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/calliope/backend.py", line 809, in Run
    resources = command_instance.Run(args)
  File "xxxxxxxx/google-cloud-sdk/lib/surface/app/deploy.py", line 123, in Run
    return deploy_util.RunDeploy(
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/command_lib/app/deploy_util.py", line 690, in RunDeploy
    deployer.Deploy(
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/command_lib/app/deploy_util.py", line 471, in Deploy
    self.api_client.DeployService(new_version.service, new_version.id,
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/api_lib/app/appengine_api_client.py", line 230, in DeployService
    return operations_util.WaitForOperation(
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/api_lib/app/operations_util.py", line 307, in WaitForOperation
    completed_operation = waiter.WaitFor(
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/api_lib/util/waiter.py", line 261, in WaitFor
    operation = PollUntilDone(
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/api_lib/util/waiter.py", line 322, in PollUntilDone
    operation = retryer.RetryOnResult(
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/core/util/retry.py", line 249, in RetryOnResult
    if not should_retry(result, state):
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/api_lib/util/waiter.py", line 320, in _IsNotDone
    return not poller.IsDone(operation)
  File "xxxxxxxx/google-cloud-sdk/lib/googlecloudsdk/api_lib/app/operations_util.py", line 182, in IsDone
    raise OperationError(requests.ExtractErrorMessage(
googlecloudsdk.api_lib.app.operations_util.OperationError: Error Response: [13] An internal error occurred.
ERROR: (gcloud.app.deploy) Error Response: [13] An internal error occurred.

The app.yaml is very basic and when I run my application locally, it runs fine. Here is the app.yaml:

entrypoint: bundle exec rails server Puma -p $PORT
env: flex
runtime: ruby
env_variables:
  RAILS_ENV: "production"
automatic_scaling:
  min_num_instances: 1
  max_num_instances: 2

I tried looking at Logs Explorer to see if there was any more details as to why the failure is happening but no luck. Any insight on how to debug further would be greatly appreciated!

Update: I didn't notice but think it could be failing due to the application.tailwind.css file not existing in the output below. I'm not sure if that's actually the issue as it doesn't look fatal and doesn't indicate it's an error:

Step #1: When you HTTParty, you must party hard!
Step #1: Removing intermediate container 7bda307caaa7
Step #1:  ---> bef7a98a7ec9
Step #1: Step 12/15 : RUN bundle exec rake assets:precompile || true
Step #1:  ---> Running in e87dc15a12c0
Step #1: Specified input file /app/app/assets/stylesheets/application.tailwind.css does not exist.
Step #1: I, [2022-04-26T00:10:39.725889 #7]  INFO -- : Writing /app/public/assets/application-37665e39018e5008ea3f942889791a8f602d3322c45b85d7e8470a13f7f59910.css
Step #1: I, [2022-04-26T00:10:39.726136 #7]  INFO -- : Writing /app/public/assets/application-37665e39018e5008ea3f942889791a8f602d3322c45b85d7e8470a13f7f59910.css.gz
Step #1: Removing intermediate container a87dc15a12c0
Step #1:  ---> 423dafb9ba66
Step #1: Step 13/15 : FROM augmented-base
Step #1:  ---> 3958643d64af
Step #1: Step 14/15 : COPY --from=app-build /app/ /app/
Step #1:  ---> 59e2cd88ca1a
Step #1: Step 15/15 : CMD exec bundle exec rails server Puma -p $PORT
Step #1:  ---> Running in 73a5dd7ff3d2
Step #1: Removing intermediate container 73a5dd7ff3d2
Step #1:  ---> c4785ef8d392
Step #1: Successfully built c4785ef8d392
Step #1: Successfully tagged us.gcr.io/xxxxxxxxxxxx/default.202220425t163957:latest
Finished Step #1
PUSH
Pushing us.gcr.io/xxxxxxxxxxxxxx/appengine/default.202220425t163957:latest
The push refers to repository [us.gcr.io/xxxxxxxxxxxxxxx/appengine/default.202220425t163957]
3642fcf3d105: Preparing
5ba2d620e9b8: Preparing
e6c3ee2a1dc7: Preparing
f254496b0294: Preparing
165e9843257f: Preparing
471f69049b89: Preparing
84ff92691f90: Preparing
b49bce339f97: Preparing
dcb7197db903: Preparing
84ff92691f90: Waiting
b49bce339f97: Waiting
471f69049b89: Waiting
dcb7197db903: Waiting
f254496b0294: Layer already exists
165e9843257f: Layer already exists
84ff92691f90: Layer already exists
471f69049b89: Layer already exists
b49bce339f97: Layer already exists
dcb7197db903: Layer already exists
e6c3ee2a1dc7: Pushed
5ba2d620e9b8: Pushed
3642fcf3d105: Pushed
latest: digest: sha256:f6ca40a7106d837827093fb5a9ac1e26b9576b9a877a28be90b2242a63510444 size: 2209
DONE
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Updating service [default] (this may take several minutes)...failed.                                                                                                                             
ERROR: (gcloud.app.deploy) Error Response: [13] An internal error occurred.

Update #2: After adding the missing asset file, it looks like another error is thrown:

Step #1: Browserslist: caniuse-lite is outdated. Please run:
Step #1:   npx browserslist@latest --update-db
Step #1:   Why you should do it regularly: https://github.com/browserslist/browserslist#browsers-data-updating
Step #1: 
Step #1: Done in 979ms.
Step #1: I, [2022-04-30T16:05:52.871250 #8]  INFO -- : Writing /app/public/assets/manifest-90aab26ade71e747f745b1227b433fd7d580a54f279ee2be6e1a67bb326bf03a.js
Step #1: I, [2022-04-30T16:05:52.872327 #8]  INFO -- : Writing /app/public/assets/manifest-90aab26ade71e747f745b1227b433fd7d580a54f279ee2be6e1a67bb326bf03a.js.gz
Step #1: I, [2022-04-30T16:05:52.873483 #8]  INFO -- : Writing /app/public/assets/application-79acb896e19757de4ac1a94d7a9ed4649c1c87e146846d806f93dcdc062c6a4d.css
Step #1: I, [2022-04-30T16:05:52.873736 #8]  INFO -- : Writing /app/public/assets/application-79acb896e19757de4ac1a94d7a9ed4649c1c87e146846d806f93dcdc062c6a4d.css.gz
Step #1: I, [2022-04-30T16:05:52.874356 #8]  INFO -- : Writing /app/public/assets/application.tailwind-727aaabcff3ab779544847b78f71b65d03963692205b3bba1fc81dbe96d77906.css
Step #1: I, [2022-04-30T16:05:52.874663 #8]  INFO -- : Writing /app/public/assets/application.tailwind-727aaabcff3ab779544847b78f71b65d03963692205b3bba1fc81dbe96d77906.css.gz
Step #1: I, [2022-04-30T16:05:52.875667 #8]  INFO -- : Writing /app/public/assets/tailwind-caafe944543690893f7a5b6d72c03227f5be6e8c9e571a9e8aecf63f7316a78e.css
Step #1: I, [2022-04-30T16:05:52.875936 #8]  INFO -- : Writing /app/public/assets/tailwind-caafe944543690893f7a5b6d72c03227f5be6e8c9e571a9e8aecf63f7316a78e.css.gz
Step #1: Removing intermediate container 76f1174ba452
Step #1:  ---> a6519edd8b36
Step #1: Step 14/16 : FROM augmented-base
Step #1:  ---> f38133bf5629
Step #1: Step 15/16 : COPY --from=app-build /app/ /app/
Step #1:  ---> d7b25b26c95f
Step #1: Step 16/16 : CMD exec bundle exec rails server -p $PORT
Step #1:  ---> Running in 23b0e8a83de9
Step #1: Removing intermediate container 23b0e8a83de9
Step #1:  ---> f251ce1fef21
Step #1: Successfully built f251ce1fef21
Step #1: Successfully tagged us.gcr.io/xxxxx/appengine/default.20220430t083823:latest
Finished Step #1
PUSH
Pushing us.gcr.io/xxxxxx/appengine/default.20220430t083823:latest
The push refers to repository [us.gcr.io/xxxxxxx/appengine/default.20220430t083823]
89e97bb1c87a: Preparing
a8b309f5a6e7: Preparing
653b234c4329: Preparing
2fe581f14dfe: Preparing
f254496b0294: Preparing
165e9843257f: Preparing
471f69049b89: Preparing
84ff92691f90: Preparing
b49bce339f97: Preparing
dcb7197db903: Preparing
165e9843257f: Waiting
471f69049b89: Waiting
84ff92691f90: Waiting
b49bce339f97: Waiting
dcb7197db903: Waiting
f254496b0294: Layer already exists
165e9843257f: Layer already exists
471f69049b89: Layer already exists
84ff92691f90: Layer already exists
b49bce339f97: Layer already exists
dcb7197db903: Layer already exists
2fe581f14dfe: Pushed
a8b309f5a6e7: Pushed
653b234c4329: Pushed
89e97bb1c87a: Pushed
latest: digest: sha256:180ac085461395ad3bd791f02ac93cd09db7ca8f2e30160560b867974e9e73fc size: 2420
DONE
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Updating service [default] (this may take several minutes)...failed.                                                                                                                             
ERROR: (gcloud.app.deploy) Error Response: [13] An internal error occurred.