UnboundLocalError: local variable 'lshw' referenced before assignment

[Taihsiang Ho]

On some systems we will get this message[1] when running SRU.

Stable PPA is used:
ubuntu@201708-25694:~$ dpkg -l "*plainbox*" "*checkbox*"
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==================================-========================-============-=======================================================
ii checkbox-ng 1.6.0~ppa~ubuntu19.10.1 all CheckBoxNG test runner
un plainbox <none> <none> (no description available)
ii plainbox-provider-checkbox 0.50.0~ppa~ubuntu19.10.1 amd64 CheckBox provider for PlainBox
ii plainbox-provider-resource-generic 0.42.0~ppa~ubuntu19.10.1 amd64 CheckBox generic resource jobs provider
ii plainbox-provider-sru 1.14.0~ppa~ubuntu19.10.1 all CheckBox SRU jobs provider
ii python3-checkbox-ng 1.6.0~ppa~ubuntu19.10.1 all CheckBoxNG test runner (Python 3 library)
ii python3-checkbox-support 0.43.0~ppa~ubuntu19.10.1 all collection of Python modules used by PlainBox providers
un python3-plainbox <none> <none> (no description available)
ubuntu@201708-25694:~$

Several submission error urls:
 - eoan on 201708-25694 Dell XPS 13 9370
https://certification.canonical.com/hardware/201708-25694/submission/157035/test/150/result/11900834/

  - https://certification.canonical.com/hardware/201708-25694/submission/154095/test/150/result/11663686/

[1]
ERROR:root:Unable to parse JSON: Expecting ',' delimiter: line 24 column 8 (char 588)
Traceback (most recent call last):
  File "/tmp/nest-wb0h8_me.440b17a5ec0d6b6a647c77b4732450c74e22a9f9253d55dd13ad0aa9afafc812/memory_compare", line 138, in <module>
    sys.exit(main())
  File "/tmp/nest-wb0h8_me.440b17a5ec0d6b6a647c77b4732450c74e22a9f9253d55dd13ad0aa9afafc812/memory_compare", line 101, in main
    installed_memory = HumanReadableBytes(get_installed_memory_size())
  File "/tmp/nest-wb0h8_me.440b17a5ec0d6b6a647c77b4732450c74e22a9f9253d55dd13ad0aa9afafc812/memory_compare", line 62, in get_installed_memory_size
    lshw.run(result)
  File "/usr/lib/python3/dist-packages/checkbox_support/parsers/lshwjson.py", line 47, in run
    self._parse_lshw(lshw, result)
UnboundLocalError: local variable 'lshw' referenced before assignment

[Rod Smith (rodsmith)]

This bug is caused by invalid lshw output, and I don't see any obvious workaround short of a serious re-write of the memory/info test. Others are working on the lshw bug; with any luck a fix will be available before Ubuntu 20.04 is released. If not, we may need to drop or seriously re-work the memory/info test; but with progress being made on the underlying bug, it seems best to wait a bit before committing resources to a workaround. See also bug #1840462, which closely parallels this one.