Why is a job failing with job status of "Failed because the previous SCM Update failed"?

Issue

Job is failing is failing with the following error messages but SCM Update job is not appearing in the jobs list

Failed because the previous SCM Update failed

"job_explanation": "Previous Task Failed: {\"job_type\": \"project_update\", \"job_name\": \"Example Project\", \"job_id\": \"14\"}",
...
"result_traceback": "Traceback (most recent call last):
  File \"/var/lib/awx/venv/awx/lib64/python3.9/site-packages/awx/main/tasks/jobs.py\", line 492, in run
    self.build_project_dir(self.instance, private_data_dir)
  File \"/var/lib/awx/venv/awx/lib64/python3.9/site-packages/awx/main/tasks/jobs.py\", line 1086, in build_project_dir
    self.sync_and_copy(job.project, private_data_dir, scm_branch=job.scm_branch)
  File \"/var/lib/awx/venv/awx/lib64/python3.9/site-packages/awx/main/tasks/jobs.py\", line 783, in sync_and_copy
    return self.sync_and_copy_without_lock(project, private_data_dir, scm_branch=scm_branch)
  File \"/var/lib/awx/venv/awx/lib64/python3.9/site-packages/awx/main/tasks/jobs.py\", line 739, in sync_and_copy_without_lock
    sync_task.run(local_project_sync.id)
  File \"/var/lib/awx/venv/awx/lib64/python3.9/site-packages/awx/main/tasks/jobs.py\", line 92, in _wrapped
    return f(self, *args, **kwargs)
  File \"/var/lib/awx/venv/awx/lib64/python3.9/site-packages/awx/main/tasks/signals.py\", line 81, in _wrapped
    return f(*args, **kwargs)
  File \"/var/lib/awx/venv/awx/lib64/python3.9/site-packages/awx/main/tasks/jobs.py\", line 657, in run
    raise AwxTaskError.TaskError(self.instance, rc)
Exception: project_update 14 (failed) encountered an error (rc=None), please see task stdout for details.
",