Alter the main search query to search posts by coauthor user name

I ended up figuring this out by realizing that I could build a list of coauthor id’s using the template tags that ship with the coauthors plugin. Next, I observed how WordPress core does joins to query by taxonomy, but var_dumping the posts_request on a term archive page. At that point, I just had to swap in my coauthor ID’s and it works great.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)