nginx redirect and anubisn

[Greg Troxel <gdt%lexort.com@localhost>]

I am tring to use anubis with nginx (both from pkgsrc, up-to-date with
head) and having a problem with redirects.

Mostly the instructions on how to set it up work fine.   external
requests get the anubis page and then end up at the
localhost:backend-port server entry in nginx and work fine.

However

  https://foo.example.com/bar

is routed via anubis back to

  http://localhost:backendport/bar

which is fine.  But then nginx returns a 301 to

  http://localhost:backendport/bar/


This is wrong because the server's external address is

  https://localhost/bar/


I am wondering if I need to create a location block that matches names
without a / and redirect to where I want with the /, but it seems like
everyone should have the same problem and there should be an nginx
config to give the scheme://host:port/ part that is the external view
for this server block's content.

Alternatively, can I have it just server bar/index.html when asked for
bar?

I already tried a bunch of searching and reading, without enlightenment.