I'm fine with a minor league deal of Bucholtz I guess, but I think we need to move on from Ervin. There's definite baggage there and likely minimal upside at this point.
But I think I'd prefer to ride or die with the various pitchers we have then dumpster dive for a veteran. It's not like we don't have experienced pitchers (Gibson, Odorizzi, and Pineda have all been around for a while now, and even Berrios has multiple years in MLB), so unless we sign a guy who improves the top end (my "better than Gibson" plan) I think we're better off finding out if Mejia, Gonsalves, Stewart, or Romero are going to be options as consistent MLB starters for this team. Having three guys in AAA (or 2 + a guy in the 'pen) isn't bad depth, really. And Lewis Thorpe might be knocking on the door this summer too.
Mejia's issue is not getting deep enough into games, but we know he can pitch effectively at this level. Working with an opener might be the solution for him to get the team enough innings out of that 5th slot.