ERROR: (gcloud.app.deploy) INVALID_ARGUMENT: unable to resolve source - google-app-engine

Question

I am trying to deploy a go 1.11 runtime that used to work, but recently I've been getting: ERROR: (gcloud.app.deploy) INVALID_ARGUMENT: unable to resolve source errors.
Nothing in my app.yaml has changed, and the error message isn't helpful to understand what the issue could be. I ran it with the --verbosity=debug flag and get:
Building and pushing image for service [apiv1]
DEBUG: Could not call git with args ('config', '--get-regexp', 'remote\\.(.*)\\.url'): Command '['git', 'config', '--get-regexp', 'remote\\.(.*)\\.url']' returned non-zero exit status 1
INFO: Could not generate [source-context.json]: Could not list remote URLs from source directory: /var/folders/18/k3w6w7f169xg4mypdwj7p4_c0000gn/T/tmp6IkZKx/tmphibUAo
Stackdriver Debugger may not be configured or enabled on this application. See https://cloud.google.com/debugger/ for more information.
INFO: Uploading [/var/folders/18/k3w6w7f169xg4mypdwj7p4_c0000gn/T/tmpVHKXol/src.tgz] to [staging.wildfire-app-backend.appspot.com/asia.gcr.io/wildfire-app-backend/appengine/apiv1.20190506t090359:latest]
DEBUG: Using runtime builder root [gs://runtime-builders/]
DEBUG: Loading runtimes manifest from [gs://runtime-builders/runtimes.yaml]
INFO: Reading [<googlecloudsdk.api_lib.storage.storage_util.ObjectReference object at 0x105ca9b10>]
DEBUG: Resolved runtime [go1.11] as build configuration [gs://runtime-builders/go-1.11-builder-20181217154124.yaml]
INFO: Using runtime builder [gs://runtime-builders/go-1.11-builder-20181217154124.yaml]
INFO: Reading [<googlecloudsdk.api_lib.storage.storage_util.ObjectReference object at 0x105b03b50>]
DEBUG: (gcloud.app.deploy) INVALID_ARGUMENT: unable to resolve source
Traceback (most recent call last):
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/calliope/cli.py", line 985, in Execute
resources = calliope_command.Run(cli=self, args=args)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/calliope/backend.py", line 795, in Run
resources = command_instance.Run(args)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/surface/app/deploy.py", line 90, in Run
parallel_build=False)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/command_lib/app/deploy_util.py", line 636, in RunDeploy
flex_image_build_option=flex_image_build_option)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/command_lib/app/deploy_util.py", line 411, in Deploy
image, code_bucket_ref, gcr_domain, flex_image_build_option)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/command_lib/app/deploy_util.py", line 287, in _PossiblyBuildAndPush
self.deploy_options.parallel_build)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/api_lib/app/deploy_command_util.py", line 450, in BuildAndPushDockerImage
return _SubmitBuild(build, image, project, parallel_build)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/api_lib/app/deploy_command_util.py", line 483, in _SubmitBuild
build, project=project)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/api_lib/cloudbuild/build.py", line 149, in ExecuteCloudBuild
build_op = self.ExecuteCloudBuildAsync(build, project)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/api_lib/cloudbuild/build.py", line 133, in ExecuteCloudBuildAsync
build=build,))
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/googlecloudsdk/third_party/apis/cloudbuild/v1/cloudbuild_v1_client.py", line 205, in Create
config, request, global_params=global_params)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/third_party/apitools/base/py/base_api.py", line 731, in _RunMethod
return self.ProcessHttpResponse(method_config, http_response, request)
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/third_party/apitools/base/py/base_api.py", line 737, in ProcessHttpResponse
self.__ProcessHttpResponse(method_config, http_response, request))
File "/usr/local/Caskroom/google-cloud-sdk/latest/google-cloud-sdk/lib/third_party/apitools/base/py/base_api.py", line 604, in __ProcessHttpResponse
http_response, method_config=method_config, request=request)
HttpBadRequestError: HttpError accessing <https://cloudbuild.googleapis.com/v1/projects/wildfire-app-backend/builds?alt=json>: response: <{'status': '400', 'content-length': '114', 'x-xss-protection': '0'
, 'x-content-type-options': 'nosniff', 'transfer-encoding': 'chunked', 'vary': 'Origin, X-Origin, Referer', 'server': 'ESF', '-content-encoding': 'gzip', 'cache-control': 'private', 'date': 'Mon, 06 May 2
019 16:04:41 GMT', 'x-frame-options': 'SAMEORIGIN', 'alt-svc': 'quic=":443"; ma=2592000; v="46,44,43,39"', 'content-type': 'application/json; charset=UTF-8'}>, content <{
"error": {
"code": 400,
"message": "unable to resolve source",
"status": "INVALID_ARGUMENT"
}
}
>
ERROR: (gcloud.app.deploy) INVALID_ARGUMENT: unable to resolve
Any advice would be useful, I also tried it with gcloud beta, I rotated my credentials and was of no use. My user has Owner role, but I added individually all the roles that might be necessary
App Engine Admin
App Engine Code Viewer
App Engine Deployer
App Engine Service Admin
Project Billing Manager
Cloud Build Service Account
Cloud Build Editor
Cloud Build Viewer
Owner
Storage Admin

Answer 1

Try disabling and enabling the Cloud Build API in your project so a new service account is created, then try to deploy again.
This ensures that Cloud Build has permission to start builds (the service account name should look like project-number#cloudbuild.gserviceaccount.com).

Answer 2

I found that it took a while for the API permissions to propagate fully.
I had this error after enabling the App Engine Admin API, but I waited a few minutes and tried again and it worked fine.

Answer 3

Cloud Build uses a service account instead of your user credential, so adding roles to your user won't help in this case.
You should be able to manually add the service account, [project-number]#cloudbuild.gserviceaccount.com, back to your account without re-enabling the API. Some users are known to delete random service accounts they don't recognize, which can sometimes cause this issue.
In summary, check if the service account exists. If so, give it all the roles it needs; if not, then create it and give it all the role it needs.