I've been successfully running the local development server daily and have made no changes except that I called "gcloud components update" just before it stopped working. Now I get: 

```
..snip...    <<PATH TO MY SDK>>/google-cloud-sdk/platform/google_appengine/google/appengine/tools/devappserver2/application_configuration.py", line 518, in _parse_configuration
        with open(configuration_path) as f:
    IOError: [Errno 2] No such file or directory: 'app.yaml'

```

Of course app.yaml hasn't moved. 

Any thoughts?
['https://Stackoverflow.com/questions/52653776', 'https://Stackoverflow.com', 'https://Stackoverflow.com/users/10458445/']
You may create `make` file and have something like this:

```
export SDK=dev_appserver.py
export APP_PATH=${CURDIR}

run:
    $(SDK) $(APP_PATH)/path-to/app.yaml

```

And just use it with: `make run` so you don't have to worry about paths.
This worked for me: in `app.yaml`, change

`runtime: go`

to

`runtime: go111`