Using a valid token without the right permissions gives unhelpful error

Nobody has claimed this yet.

When going through the [MTS tutorial](https://docs.mapbox.com/help/tutorials/get-started-mts-and-tilesets-cli/#create-a-tileset-source), I accidentally used my default public token which does not have the correct permissions.

```sh
export MAPBOX_ACCESS_TOKEN=pk.....`
tilesets upload-source newtang populated-places-source ./populated_places.geojson.ld
```

I received a long, repetitive stack trace:
Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 670, in urlopen
httplib_response = self._make_request(
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 392, in _make_request
conn.request(method, url, **httplib_request_kw)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1240, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1286, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1235, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1045, in _send_output
self.send(chunk)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 967, in send
self.sock.sendall(data)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1204, in sendall
v = self.send(byte_view[count:])
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1173, in send
return self._sslobj.write(data)
BrokenPipeError: [Errno 32] Broken pipe

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/requests/adapters.py", line 439, in send
resp = conn.urlopen(
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 726, in urlopen
retries = retries.increment(
File "/usr/local/lib/python3.8/site-packages/urllib3/util/retry.py", line 410, in increment
raise six.reraise(type(error), error, _stacktrace)
File "/usr/local/lib/python3.8/site-packages/urllib3/packages/six.py", line 734, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 670, in urlopen
httplib_response = self._make_request(
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 392, in _make_request
conn.request(method, url, **httplib_request_kw)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1240, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1286, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1235, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1045, in _send_output
self.send(chunk)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 967, in send
self.sock.sendall(data)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1204, in sendall
v = self.send(byte_view[count:])
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1173, in send
return self._sslobj.write(data)
urllib3.exceptions.ProtocolError: ('Connection aborted.', BrokenPipeError(32, 'Broken pipe'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/bin/tilesets", line 8, in
sys.exit(cli())
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 829, in __call__
return self.main(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 782, in main
rv = self.invoke(ctx)
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 1066, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 610, in invoke
return callback(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/click/decorators.py", line 21, in new_func
return f(get_current_context(), *args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/mapbox_tilesets/scripts/cli.py", line 518, in upload_source
return _upload_source(
File "/usr/local/lib/python3.8/site-packages/mapbox_tilesets/scripts/cli.py", line 594, in _upload_source
resp = getattr(s, method)(
File "/usr/local/lib/python3.8/site-packages/requests/sessions.py", line 578, in post
return self.request('POST', url, data=data, json=json, **kwargs)
File "/usr/local/lib/python3.8/site-packages/requests/sessions.py", line 530, in request
resp = self.send(prep, **send_kwargs)
File "/usr/local/lib/python3.8/site-packages/requests/sessions.py", line 643, in send
r = adapter.send(request, **kwargs)
File "/usr/local/lib/python3.8/site-packages/requests/adapters.py", line 498, in send
raise ConnectionError(err, request=request)
requests.exceptions.ConnectionError: ('Connection aborted.', BrokenPipeError(32, 'Broken pipe'))
[~/source/mts-tutorial]$ tilesets upload-source newtang populated-places-source ./populated_places.geojson.ld --token=pk...
Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 670, in urlopen
httplib_response = self._make_request(
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 392, in _make_request
conn.request(method, url, **httplib_request_kw)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1240, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1286, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1235, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1045, in _send_output
self.send(chunk)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 967, in send
self.sock.sendall(data)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1204, in sendall
v = self.send(byte_view[count:])
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1173, in send
return self._sslobj.write(data)
BrokenPipeError: [Errno 32] Broken pipe

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/lib/python3.8/site-packages/requests/adapters.py", line 439, in send
resp = conn.urlopen(
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 726, in urlopen
retries = retries.increment(
File "/usr/local/lib/python3.8/site-packages/urllib3/util/retry.py", line 410, in increment
raise six.reraise(type(error), error, _stacktrace)
File "/usr/local/lib/python3.8/site-packages/urllib3/packages/six.py", line 734, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 670, in urlopen
httplib_response = self._make_request(
File "/usr/local/lib/python3.8/site-packages/urllib3/connectionpool.py", line 392, in _make_request
conn.request(method, url, **httplib_request_kw)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1240, in request
self._send_request(method, url, body, headers, encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1286, in _send_request
self.endheaders(body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1235, in endheaders
self._send_output(message_body, encode_chunked=encode_chunked)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 1045, in _send_output
self.send(chunk)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py", line 967, in send
self.sock.sendall(data)
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1204, in sendall
v = self.send(byte_view[count:])
File "/usr/local/Cellar/python@3.8/3.8.4/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py", line 1173, in send
return self._sslobj.write(data)
urllib3.exceptions.ProtocolError: ('Connection aborted.', BrokenPipeError(32, 'Broken pipe'))

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/usr/local/bin/tilesets", line 8, in
sys.exit(cli())
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 829, in __call__
return self.main(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 782, in main
rv = self.invoke(ctx)
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 1259, in invoke
return _process_result(sub_ctx.command.invoke(sub_ctx))
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 1066, in invoke
return ctx.invoke(self.callback, **ctx.params)
File "/usr/local/lib/python3.8/site-packages/click/core.py", line 610, in invoke
return callback(*args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/click/decorators.py", line 21, in new_func
return f(get_current_context(), *args, **kwargs)
File "/usr/local/lib/python3.8/site-packages/mapbox_tilesets/scripts/cli.py", line 518, in upload_source
return _upload_source(
File "/usr/local/lib/python3.8/site-packages/mapbox_tilesets/scripts/cli.py", line 594, in _upload_source
resp = getattr(s, method)(
File "/usr/local/lib/python3.8/site-packages/requests/sessions.py", line 578, in post
return self.request('POST', url, data=data, json=json, **kwargs)
File "/usr/local/lib/python3.8/site-packages/requests/sessions.py", line 530, in request
resp = self.send(prep, **send_kwargs)
File "/usr/local/lib/python3.8/site-packages/requests/sessions.py", line 643, in send
r = adapter.send(request, **kwargs)
File "/usr/local/lib/python3.8/site-packages/requests/adapters.py", line 498, in send
raise ConnectionError(err, request=request)
requests.exceptions.ConnectionError: ('Connection aborted.', BrokenPipeError(32, 'Broken pipe'))

It would be great to see a more helpful error message if possible. This could be the issue at the heart of this ticket as well: https://github.com/mapbox/tilesets-cli/issues/101.

Start with mapbox_tilesets/scripts/cli.py at upload_source and _upload_source, identified in the traceback, and reproduce the tilesets upload-source command with a valid token lacking the required permissions. Trace how the response is handled and make the failure report the permission problem instead of the repetitive connection traceback. Done means the command gives a concise, actionable error for this token scenario.

Written by the indexing model from the issue text.