3.7.0 fatal error in my VVV test site

The 3.7.0 release isn’t playing nicely on my development sites (which run inside VVV). Example error:

Fatal error: Uncaught Error: Cannot use object of type WP_Error as array in /srv/www/16mm.test/public_html/wp-content/plugins/maintenance/includes/functions.php:742 Stack trace: #0 /srv/www/16mm.test/public_html/wp-content/plugins/maintenance/includes/functions.php(782): mtnc_insert_attach_sample_files() #1 /srv/www/16mm.test/public_html/wp-content/plugins/maintenance/includes/functions.php(27): mtnc_get_default_array() #2 /srv/www/16mm.test/public_html/wp-content/plugins/maintenance/includes/update.php(24): mtnc_get_plugin_options() #3 /srv/www/16mm.test/public_html/wp-content/plugins/maintenance/includes/update.php(11): mtnc_update() #4 /srv/www/16mm.test/public_html/wp-includes/class-wp-hook.php(286): mtnc_version_check(”) #5 /srv/www/16mm.test/public_html/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #6 /srv/www/16mm.test/public_html/wp-includes/plugin.php(465): WP_Hook->do_action(Array) #7 /srv/www/16mm.test/public_html/wp-admin/admin.php(169): do_action(‘admin_init’) #8 /srv/www/16mm.test/ in /srv/www/16mm.test/public_html/wp-content/plugins/maintenance/includes/functions.php on line 742
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This seems to come down to VVV’s use of an untrusted certificate, and the plugin’s use of wp_remote_get() to get the content of its own files e.g. in includes/functions.php lines 742 (the example above) and line 803 (on another of my test sites).