As soon as one has "debug level = 1", some debugging information gets printed on stdout. I believe that should be done on stderr. For example I have one app using libsmbclient, which output is parsed as XML. That debugging information makes the parser complains.
Changed severity from "normal" to "enhancement". It should be possible to make the requested change, and I'll look into it when I get a chance.
Added new option to log debug messages to stderr instead of stdout. See examples/libsmbclient/testbrowse.c for an example of using it.