Currently the virt-v2v tracing is inconsistent. Some traces/debug messages end up on stdout and some on stderr. To obtain useful log one must merge stdout and stderr streams and store both. While it is generally not a problem, this may complicate things when virt-v2v is not run manualy but is used inside some other tool.

Also since the tracing is rather aggressive it can make it difficult to find the error message among the debug messages in case of an error. It might be preferable to put all the traces to stdout and keep stderr for error reporting only. This is again mainly to simplify situation when virt-v2v is used in some other tool.