Comment 5 for bug 1822712

My sources.list file has this first deb line:

deb [ arch=riscv64 ] http://ports.ubuntu.com/ubuntu-ports/ lunar main restricted

root@unmatched2:/var/crash# apport-retrace --gdb --sandbox system --cache ~/.cache/apport-retrace/ _usr_bin_qemu-x86_64-static.1000.crash
Traceback (most recent call last):
  File "/usr/bin/apport-retrace", line 743, in <module>
    main()
  File "/usr/bin/apport-retrace", line 487, in main
    sandbox, cache, outdated_msg = apport.sandboxutils.make_sandbox(
                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/apport/sandboxutils.py", line 277, in make_sandbox
    pkg = packaging.get_file_package(
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/apport/packaging_impl/apt_dpkg.py", line 536, in get_file_package
    return self._search_contents(file, map_cachedir, release, arch)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/apport/packaging_impl/apt_dpkg.py", line 1478, in _search_contents
    self._get_mirror(),
    ^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/apport/packaging_impl/apt_dpkg.py", line 1426, in _get_mirror
    self._mirror = self._get_primary_mirror_from_apt_sources(
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/apport/packaging_impl/apt_dpkg.py", line 1414, in _get_primary_mirror_from_apt_sources
    raise SystemError(
SystemError: cannot determine default mirror: /etc/apt/sources.list does not contain a valid deb line
root@unmatched2:/var/crash#