Provide simple debug data in WSOD emails

[Clorith]

Errors are terrible, if you're not familiar with troubleshooting, they're even worse.

What happens if you get the dreaded email from WordPress, your site has crashed, you know something broke, but are lost beyond that, so you go to seek help in fixing it. Unfortunately you can't help others, help you. They asked you something simple; what version of the Plugin X are you using? You have no idea, you feel lost, those helping you feel frustration, it's bad times all around.

But wait, there, in the distance, a shimmering light!

When an error email is sent, let's include a new section, prefix it with When seeking help with this issue, you may be asked for some of the following information, and then add the current WP version, the plugin version of that which broke, what theme is in use would also be handy, this is all information we can readily grab and provide after all!

[Clorith]

48090.patch​ expands the email sent with the most commonly asked questions when something crashes, namely the WordPress version, what theme is being used, and the version of the plugin that caused an issue (if caused by a plugin).

These are all created as an associated array, which is filterable through recovery_email_debug_info, making it possible to add more details in some scenarios.

The information sent is intentionally constricted on our end, to avoid information overload and confusion for the end user.

The patch also moves the code for fetching plugin details out of the get_cause() function to a separate get_plugin() call so that it can be reused more easily when building the error email.

[TimothyBlynJacobs]

This would be awesome. I think adding the PHP version would be highly valuable here as well.

[Clorith]

Sounds reasonable as a likely cause of a failure, 48090.2.patch​ includes this.

[davidbaumwald]

With version 5.3 Beta 1 landing today, this is being moved into 5.4 based on recent momentum.

[SergeyBiryukov]

In 46273:

Site Health: Include simple debug data in fatal error protection email.

Introduce recovery_email_debug_info filter for the debug information included in the email.

Props Clorith, TimothyBlynJacobs.
Fixes #48090.