I figured it out.
The content was asking for something. I cleaned everything out and it came back to me. I thought some string interpolation would just be benign but it was messing things up.
When this happens, it would be nice to have some kind of idea what the problem is, but the nginx log, set to DEBUG, didn’t mention a thing.
> On Sep 13, 2017, at 1:53 PM, kashyap k <kashya...@gmail.com
> Where is the template 'login.erb'? and what contents does it have? Any instance variables that you might not have declared, but are getting used in the template?