Send error to error_log when creating a WP_Error object

[ericlewis]

WP_Error is a generic error object for the WordPress application.

To assist with debugging, I'd like us to consider sending these error messages to PHP's error_log() function.

[ocean90]

That would be possible with #28319.

[ericlewis]

#28319 looks to be covering this topic

[nacin]

As noted in #28319:

I think my bigger concern here is that WP_Error objects are not exceptions — rarely are they "exceptional." Often, they are used as return values for functions that meet some kind of error condition, but that doesn't mean every usage meets the level of a deprecated function, notices, or PHP errors (see also: ​https://wordpress.org/plugins/log-deprecated-notices/, ​https://wordpress.org/plugins/debug-bar/).
This is basically the equivalent of logging every time a function returns false.

I think there are better things we can do here. I'm writing something up this week.