Troubleshooting#

Solutions and diagnostic guidance for common issues encountered when working with QRMI.

Job Execution Errors#

error: spank_qrmi_c, failed to acquire resource: ibm_brisbane#

Cause: This error occurs when accessing IBM Quantum backends using an Open Plan account on IBM Quantum Platform.

Check:

  1. Setup virtual environment:

python3.11 -m venv ~/{your_pyenv}
source ~/{your_pyenv}/bin/activate
pip install qiskit-ibm-runtime

  1. Create test.py:

Replace SERVICE_CRN and API_KEY values with your credentials and with your backend name.

test.py#
 1"""A testcase to check if Qiskit Session can be created with the given credentials"""
 2from qiskit_ibm_runtime import QiskitRuntimeService, Session
 3
 4SERVICE_CRN="YOUR_SERVICE_CRN"
 5API_KEY="YOUR_APIKEY" # pragma: allowlist secret
 6
 7service = QiskitRuntimeService(
 8    channel="ibm_cloud",
 9    instance=SERVICE_CRN,
10    token=API_KEY,
11)
12
13backend = service.backend("<your backend name>")
14with Session(backend=backend, max_time=1) as session:
15    print("Succeeded in obtaining a Qiskit Session")

  1. Run the test case:

python test.py

This will fail due to the error:

You are not authorized to run a session when using the open plan.

Solution:

  • Use a Premium Plan account, or

  • Use Batch execution mode`_

  • Add QRMI_IBM_QRS_SESSION_MODE environment variable with “batch” in your qrmi_config.json

 {
   "name": "ibm_brisbane",
   "type": "ibm-quantum-compute-service",
   "environment": {
       "...": "...",
       "QRMI_IBM_QRS_SESSION_MODE": "batch"
   }
}