lighttpd simple regex routing

My config looks nearly identical to the "working config" listed at the bottom of:   https://redmine.lighttpd.net/boards/2/topics/8321

Yet, it's not proxying as it should.

]$ lighttpd -v
lighttpd/1.4.53 (ssl) - a light and fast webserver






==========================================
==== START CONFIG
==========================================

debug.log-request-handling = "enable"
debug.log-condition-handling = "enable"

proxy.debug = 1
server.document-root = "/var/whatever"
server.port = 7890
server.username = "nobody"
server.groupname = "nobody"
server.modules   = (
                     "mod_alias",
                     "mod_redirect",
                     "mod_proxy",
                     "mod_rewrite"
                    )


default.proxy.server.host = "127.0.0.1"


$HTTP["url"] =~ "^/redir-xyz/(.*)" {
    url.rewrite-once = ( "^/redir-xyz/(.*)" => "/$1" )
    proxy.server = ( "" =>
                  (  "redir for xyz" =>
                      (
                         "host" => default.proxy.server.host,
                         "port" => "16201",
                      )
                   )
               )
}


==========================================
=== END CONFIG
==========================================


==========================================
==== START EXECUTION
==========================================

$ wget my.server.com:7890/redir-xyz/abc?123
--2019-05-03 13:29:28--  http://my.server.com:7890/redir-xyz/abc?123
Resolving my.server.com (my.server.com)... 1.2.3.4
Connecting to my.server.com (my.server.com)|1.2.3.4|:7890... connected.
HTTP request sent, awaiting response... 404 Not Found
2019-05-03 13:29:28 ERROR 404: Not Found.


==========================================
==== END EXECUTION
==========================================

==========================================
==== START LOG
==========================================
$ lighttpd -D -f simple.conf
2019-05-03 13:29:12: (server.c.1464) server started (lighttpd/1.4.53)
2019-05-03 13:29:12: (server.c.1493) WARNING: unknown config-key: default.proxy.server.host (ignored)
2019-05-03 13:29:19: (response.c.298) run condition
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.449) HTTP["url"] ( /redir-xyz/abc ) compare to  ^/redir-xyz/(.*)
2019-05-03 13:29:19: (configfile-glue.c.493) 1 (uncached) result: true
2019-05-03 13:29:19: (response.c.429) -- splitting Request-URI
2019-05-03 13:29:19: (response.c.430) Request-URI     :  /redir-xyz/abc?123
2019-05-03 13:29:19: (response.c.431) URI-scheme      :  http
2019-05-03 13:29:19: (response.c.432) URI-authority   :  my.server.com:7890
2019-05-03 13:29:19: (response.c.433) URI-path (raw)  :  /redir-xyz/abc
2019-05-03 13:29:19: (response.c.434) URI-path (clean):  /redir-xyz/abc
2019-05-03 13:29:19: (response.c.435) URI-query       :  123
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.500) 1 (cached) result: true
2019-05-03 13:29:19: (response.c.298) run condition
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.449) HTTP["url"] ( /abc ) compare to  ^/redir-xyz/(.*)
2019-05-03 13:29:19: (configfile-glue.c.493) 1 (uncached) result: false
2019-05-03 13:29:19: (response.c.429) -- splitting Request-URI
2019-05-03 13:29:19: (response.c.430) Request-URI     :  /abc?123
2019-05-03 13:29:19: (response.c.431) URI-scheme      :  http
2019-05-03 13:29:19: (response.c.432) URI-authority   :  my.server.com:7890
2019-05-03 13:29:19: (response.c.433) URI-path (raw)  :  /abc
2019-05-03 13:29:19: (response.c.434) URI-path (clean):  /abc
2019-05-03 13:29:19: (response.c.435) URI-query       :  123
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.500) 1 (cached) result: false
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.500) 1 (cached) result: false
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.500) 1 (cached) result: false
2019-05-03 13:29:19: (response.c.580) -- before doc_root
2019-05-03 13:29:19: (response.c.581) Doc-Root     : /var/whatever
2019-05-03 13:29:19: (response.c.582) Rel-Path     : /abc
2019-05-03 13:29:19: (response.c.583) Path         :
2019-05-03 13:29:19: (response.c.625) -- after doc_root
2019-05-03 13:29:19: (response.c.626) Doc-Root     : /var/whatever
2019-05-03 13:29:19: (response.c.627) Rel-Path     : /abc
2019-05-03 13:29:19: (response.c.628) Path         : /var/whatever/abc
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.500) 1 (cached) result: false
2019-05-03 13:29:19: (configfile-glue.c.581) === start of condition block ===
2019-05-03 13:29:19: (configfile-glue.c.500) 1 (cached) result: false
2019-05-03 13:29:19: (response.c.652) -- logical -> physical
2019-05-03 13:29:19: (response.c.653) Doc-Root     : /var/whatever
2019-05-03 13:29:19: (response.c.654) Basedir      : /var/whatever
2019-05-03 13:29:19: (response.c.655) Rel-Path     : /abc
2019-05-03 13:29:19: (response.c.656) Path         : /var/whatever/abc
2019-05-03 13:29:19: (response.c.668) -- handling physical path
2019-05-03 13:29:19: (response.c.669) Path         : /var/whatever/abc
2019-05-03 13:29:19: (response.c.144) -- file not found
2019-05-03 13:29:19: (response.c.145) Path         : /var/whatever/abc



==========================================
==== ENDLOG
==========================================