* AFAIK ```YUI_THROW_ERRNO_MSG1``` combines ```errno``` and message into a single string, so repeating errno in the message might be superfluous.
* Most probably YUI_THROW_ macro also drops a line in the log, so the preceeding ```yuiError()``` might be superfluous as well.
* In general you should consider using e.g. (```boost::format```)[http://www.boost.org/doc/libs/1_53_0/libs/format/index.html] rather than string concatenation. It also makes it easier introdrucing translations.