Jetpack Plugins: Give a more specific error message on plugin activation/deactivation/update failures

[v18]

If you try to activate a plugin that causes a fatal error, we don't currently pass that detail back from the remote site (or display it in Calypso). We indicate that the update failed, but not really why. We should ideally pass back a more descriptive reason (from the remote site), and then provide an error along the lines of what WP core does ("Plugin could not be activated because it triggered a fatal error.")

Here's a detailed example: Test on a site that requires FTP permission in order to install or update plugins. This is accomplished by setting the file permissions of wp-content to 555 (the directory itself, not necessarily the files within).

To make sure that FTP permissions are needed to install a plugin, you can try installing a plugin and get this dialog:

You can try to update a plugin and get this dialog:

When trying to update a plugin on Calypso you see an error message instead of nothing:

Step 1: Click the update link:

Step 2: Calypso shows an alert that it's trying to update the plugin:

Step 3: see error message:

The error message isn't very informative.