IBMProvider initialization fails if h/g/p has no backends

jyu00 commented 1 year ago

Information

qiskit-ibm-provider version: 0.2.0
Python version:
Operating system:

What is the current behavior?

IBMProvider() fails with

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.9/site-packages/qiskit_ibm_provider/ibm_provider.py", line 184, in __init__
    self._initialize_services()
  File "/usr/local/lib/python3.9/site-packages/qiskit_ibm_provider/ibm_provider.py", line 411, in _initialize_services
    self._backend = IBMBackendService(self, hgp)
  File "/usr/local/lib/python3.9/site-packages/qiskit_ibm_provider/ibm_backend_service.py", line 85, in __init__
    self._initialize_backends()
  File "/usr/local/lib/python3.9/site-packages/qiskit_ibm_provider/ibm_backend_service.py", line 94, in _initialize_backends
    for name, backend in hgp.backends.items():
  File "/usr/local/lib/python3.9/site-packages/qiskit_ibm_provider/hub_group_project.py", line 62, in backends
    self._backends = self._discover_remote_backends()
  File "/usr/local/lib/python3.9/site-packages/qiskit_ibm_provider/hub_group_project.py", line 82, in _discover_remote_backends
    for backend in backends:
TypeError: 'NoneType' object is not iterable

if the particular h/g/p has no backends. In this case the particular one is hub='ibm-q-internal', group='dev-cloud', project='reservations'

Steps to reproduce the problem

Initializing an account with a h/g/p that has no backends.

What is the expected behavior?

IBMProvider() doesn't fail

Suggested solutions

nonhermitian commented 1 year ago

This is also blocking me

johannesgreiner commented 1 year ago

the error seems to come up if there is any h/g/p with no backends associated with the account. I.e. provider = IBMProvider(instance="ibm-q/open/main") fails with the same error, even though the open provider clearly has backends. ( @kt474 FYI)