Version 4.2.1

This is a bug fix release.

Added

• Server type/software detection and warning. Props @felipeelia and @brandwaffle via #2835.
• Coverage of E2E tests for the activate-feature command. Props @burhandodhy via #2802.

Changed

• Sync button title attribute. Props @burhandodhy and @JakePT via #2814.
• npm run build:zip to use git archive. Props @felipeelia via #2822.

Fixed

• Fatal error related to WP-CLI timers on long-running syncs. Props @felipeelia and @przestrzal via #2820.
• Uncaught TypeError on the Settings Page. Props @burhandodhy via #2816.
• Meta values that are not dates converted into date format. Props @burhandodhy, @oscarssanchez, @tott, and @felipeelia via #2828.
• An issue where feature settings could be saved during a sync. Props @JakePT via #2823.
• Admin menu bar items are not clickable when instant results popup modal is activated. Props @MARQAS and @JakePT via #2833.
• Facet block wrongly available in the post editor. Props @oscarssanchez via #2831.
• Show Facet widgets on taxonomy archives. Props @burhandodhy and @felipeelia via #2837.
• Meta queries with 'exists' as compare operator and empty meta values handling. Props @burhandodhy via #2817.
• Sync interruption message always mentioning ElasticPress.io. Props @burhandodhy and @JakePT via #2813.
• An issue where the Related Posts block would display the wrong posts in the preview when added inside a Query Loop block. Props @JakePT via #2825.
• E2e tests for the Facets feature. Props @felipeelia via #2840.
• Intermittent error on GitHub Actions using the latest node 16 version. Props @felipeelia via #2839.

See: https://github.com/10up/ElasticPress/milestone/65?closed=1