This won't solve your issue with being unable to execute /bin/sh, but
the above does not work like that. You need to first add at least one
disk and then run the libguestfs appliance:
>> import guestfs
>> g = guestfs.GuestFS(python_return_dict=True)
>> g.add_drive("my-machine.qcow2")
>> g.launch()
>> g.list_filesystems()
{'/dev/sda1': 'xfs'}
>> g.mount('/dev/sda1', '/')
>> g.sh("test 1 == 1")
''
>> g.sh("echo yes")
'yes\n'
--
Tomáš Golembiovský <tgolembi(a)redhat.com>