Backtrace for: #<SB-THREAD:THREAD "hunchentoot-worker-127.0.0.1:35940" RUNNING {1006ACC7B3}>
0: (LENGTH T)
1: (REDUCE #<FUNCTION +> (T) :KEY #<FUNCTION LENGTH>)
2: (LACK.MIDDLEWARE.ACCESSLOG:DEFAULT-FORMATTER (:REQUEST-METHOD :GET :SCRIPT-NAME "" :PATH-INFO "/elmyra" :SERVER-NAME "localhost" :SERVER-PORT 5000 :SERVER-PROTOCOL :HTTP/1.1 ...) (200 (:CACHE-CONTROL "private" :X-FRAME-OPTIONS "DENY" :X-CONTENT-TYPE-OPTIONS "nosniff" :CONTENT-TYPE "text/html") (T)) @2022-03-21T19:10:12.853817-06:00)
3: ((LAMBDA (LACK.MIDDLEWARE.ACCESSLOG::RES) :IN "/home/asarch/quicklisp/dists/quicklisp/software/lack-20220220-git/src/middleware/accesslog.lisp") (200 (:CACHE-CONTROL "private" :X-FRAME-OPTIONS "DENY" :X-CONTENT-TYPE-OPTIONS "nosniff" :CONTENT-TYPE "text/html") (T)))
4: ((LAMBDA (LACK.MIDDLEWARE.BACKTRACE::ENV) :IN "/home/asarch/quicklisp/dists/quicklisp/software/lack-20220220-git/src/middleware/backtrace.lisp") (:REQUEST-METHOD :GET :SCRIPT-NAME "" :PATH-INFO "/elmyra" :SERVER-NAME "localhost" :SERVER-PORT 5000 :SERVER-PROTOCOL :HTTP/1.1 ...))
5: ((:METHOD HUNCHENTOOT:ACCEPTOR-DISPATCH-REQUEST (CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR T)) #<CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR (host 0.0.0.0, port 5000)> #<HUNCHENTOOT:REQUEST {10081D12B3}>) [fast-method]
6: ((:METHOD HUNCHENTOOT:HANDLE-REQUEST (HUNCHENTOOT:ACCEPTOR HUNCHENTOOT:REQUEST)) #<CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR (host 0.0.0.0, port 5000)> #<HUNCHENTOOT:REQUEST {10081D12B3}>) [fast-method]
7: ((:METHOD HUNCHENTOOT:PROCESS-REQUEST (T)) #<HUNCHENTOOT:REQUEST {10081D12B3}>) [fast-method]
8: (HUNCHENTOOT::DO-WITH-ACCEPTOR-REQUEST-COUNT-INCREMENTED #<CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR (host 0.0.0.0, port 5000)> #<FUNCTION (LAMBDA NIL :IN HUNCHENTOOT:PROCESS-CONNECTION) {10081D121B}>)
9: ((:METHOD HUNCHENTOOT:PROCESS-CONNECTION (HUNCHENTOOT:ACCEPTOR T)) #<CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR (host 0.0.0.0, port 5000)> #<USOCKET:STREAM-USOCKET {1006ACC1A3}>) [fast-method]
10: ((:METHOD HUNCHENTOOT:PROCESS-CONNECTION :AROUND (HUNCHENTOOT:ACCEPTOR T)) #<CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR (host 0.0.0.0, port 5000)> #<USOCKET:STREAM-USOCKET {1006ACC1A3}>) [fast-method]
11: ((:METHOD HUNCHENTOOT:PROCESS-CONNECTION :AROUND (CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR T)) #<CLACK.HANDLER.HUNCHENTOOT::CLACK-ACCEPTOR (host 0.0.0.0, port 5000)> #<USOCKET:STREAM-USOCKET {1006ACC1A3}>) [fast-method]
12: ((:METHOD HUNCHENTOOT::HANDLE-INCOMING-CONNECTION% (HUNCHENTOOT:ONE-THREAD-PER-CONNECTION-TASKMASTER T)) #<HUNCHENTOOT:ONE-THREAD-PER-CONNECTION-TASKMASTER {100633B713}> #<USOCKET:STREAM-USOCKET {1006ACC1A3}>) [fast-method]
13: ((LAMBDA NIL :IN BORDEAUX-THREADS::BINDING-DEFAULT-SPECIALS))
14: ((FLET SB-UNIX::BODY :IN SB-THREAD::RUN))
15: ((FLET "WITHOUT-INTERRUPTS-BODY-10" :IN SB-THREAD::RUN))
16: ((FLET SB-UNIX::BODY :IN SB-THREAD::RUN))
17: ((FLET "WITHOUT-INTERRUPTS-BODY-3" :IN SB-THREAD::RUN))
18: (SB-THREAD::RUN)
19: ("foreign function: call_into_lisp")
20: ("foreign function: funcall1")
Above backtrace due to this condition:
The value T is not of type SEQUENCE

Request:
    REQUEST-METHOD: :GET
    SCRIPT-NAME: ""
    PATH-INFO: "/elmyra"
    SERVER-NAME: "localhost"
    SERVER-PORT: 5000
    SERVER-PROTOCOL: :HTTP/1.1
    REQUEST-URI: "/elmyra"
    URL-SCHEME: "http"
    REMOTE-ADDR: "127.0.0.1"
    REMOTE-PORT: 35940
    QUERY-STRING: NIL
    RAW-BODY: #<FLEXI-STREAMS:FLEXI-IO-STREAM {10081D16A3}>
    CONTENT-LENGTH: NIL
    CONTENT-TYPE: NIL
    CLACK.STREAMING: T
    CLACK.IO: #<CLACK.HANDLER.HUNCHENTOOT::CLIENT {10081D1713}>
    HEADERS:
        host: "localhost:5000"
        user-agent: "Mozilla/5.0 (X11; Linux x86_64; rv:98.0) Gecko/20100101 Firefox/98.0"
        accept: "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8"
        accept-language: "es-MX,es;q=0.8,en-US;q=0.5,en;q=0.3"
        accept-encoding: "gzip, deflate"
        connection: "keep-alive"
        cookie: "lack.session=de943b9ceae802fb69f7d4fd29f9f98c835b4db9"
        upgrade-insecure-requests: "1"
        sec-fetch-dest: "document"
        sec-fetch-mode: "navigate"
        sec-fetch-site: "none"
        sec-fetch-user: "?1"
    COOKIES: (("lack.session" . "de943b9ceae802fb69f7d4fd29f9f98c835b4db9"))

debugger invoked on a TYPE-ERROR @52A01B19 in thread
#<THREAD "hunchentoot-worker-127.0.0.1:35940" RUNNING {1006ACC7B3}>:
  The value
    T
  is not of type
    SEQUENCE

The current thread is not at the foreground,
SB-THREAD:RELEASE-FOREGROUND has to be called in #<SB-THREAD:THREAD "main thread" RUNNING {1001998073}>
for this thread to enter the debugger.