It looks like the OS is found:
Sep 6 00:29:21 lubuntu 50mounted-tests: debug: running subtest /usr/lib/os-probes/mounted/40lsb Sep 6 00:29:21 lubuntu 40lsb: result: /dev/sda5:Ubuntu 12.04.1 LTS (12.04):Ubuntu:linux Sep 6 00:29:21 lubuntu 50mounted-tests: debug: os found by subtest /usr/lib/os-probes/mounted/40lsb
It looks like the OS is found:
Sep 6 00:29:21 lubuntu 50mounted-tests: debug: running subtest /usr/lib/ os-probes/ mounted/ 40lsb :Ubuntu: linux os-probes/ mounted/ 40lsb
Sep 6 00:29:21 lubuntu 40lsb: result: /dev/sda5:Ubuntu 12.04.1 LTS (12.04)
Sep 6 00:29:21 lubuntu 50mounted-tests: debug: os found by subtest /usr/lib/