Leapp pre-upgrade getting "Inhibitor: Local repository found (baseurl starts with file:///). Currently leapp does not support this option."

Issue

• RHEL 7 to RHEL 8 upgrade of the host using leapp fails with below error:

  [ERROR] Actor: dnf_transaction_check
  Message: DNF execution failed with non zero exit code.
  STDOUT:
  rhel-8-for-x86_64-baseos-rpms                   0.0  B/s |   0  B     00:00    
  
  STDERR:
  Failed to create directory /var/lib/leapp/el8userspace//sys/fs/selinux: Read-only file system
  Failed to create directory /var/lib/leapp/el8userspace//sys/fs/selinux: Read-only file system
  Errors during downloading metadata for repository 'BaseOS':
   - Curl error (37): Couldn't read a file:// file for file:///mnt/iso/BaseOS/repodata/repomd.xml [Couldn't open file /mnt/iso/BaseOS/repodata/repomd.xml]
  Error: Failed to download metadata for repo 'BaseOS': Cannot download repomd.xml: Cannot download repodata/repomd.xml: All mirrors were tried