[STUMP] 'nil is not type screen' error

[Brian Zwahr]

I've seen this elsewhere on Google and possibly on this list, but I've never seen a solution. At the suggestion of the IRC channel, I'm posting here. I'm getting an error like "nil is not of type stumpwm:screen'. I figured I'd give my information and backtrace to help fix this error and get a solution.

Using Gentoo Linux:
stumpwm-0.9.5-r8 
xorg-server-1.5.3-r6

Here is the backtrace:
1: (BACKTRACE 128 #<SYNONYM-STREAM :SYMBOL SB-SYS:*STDERR* {90AF9A9}>)
2: (SB-DEBUG::DEBUGGER-DISABLED-HOOK
    #<TYPE-ERROR {B3AB219}>
    #<unavailable argument>)
3: (INVOKE-DEBUGGER #<TYPE-ERROR {B3AB219}>)
4: (ERROR TYPE-ERROR)[:EXTERNAL]
5: (SB-KERNEL::OBJECT-NOT-TYPE-ERROR-HANDLER
    #<unavailable argument>
    #.(SB-SYS:INT-SAP #XB7B0A8C8)
    #<SB-ALIEN-INTERNALS:ALIEN-VALUE :SAP #XB7B0A59C :TYPE (*
                                                            (STRUCT
                                                             SB-VM::OS-CONTEXT-T-STRUCT))>
    (14 78))
6: (SB-KERNEL:INTERNAL-ERROR
    #.(SB-SYS:INT-SAP #XB7B0A59C)
    #<unavailable argument>)
7: ("foreign function: #x80641DB")
8: ("foreign function: #x8052B88")
9: ("foreign function: #x805817D")
10: ("foreign function: #x805606E")
11: (STUMPWM::ECHO-STRING-LIST
     NIL
12: (XLIB::REPORT-ERROR
     #<XLIB:DISPLAY :0 (The X.Org Foundation R10503000)>
     15
     XLIB:NAME-ERROR)[:EXTERNAL]
13: (XLIB::READ-ERROR-INPUT
     #<XLIB:DISPLAY :0 (The X.Org Foundation R10503000)>
     28
     #S(XLIB::REPLY-BUFFER
        :SIZE 32
        :IBUF8 #(0 15 28 0 6 0 96 0 0 0 45 0 236 221 193 191 54 0 14 0 0 0 0 0
                 244 239 27 8 48 219 78 8)
        :NEXT NIL
        :DATA-SIZE 32)
     #<SB-THREAD:THREAD "initial thread" RUNNING {B30E7E9}>)
14: (XLIB::READ-INPUT
     #<XLIB:DISPLAY :0 (The X.Org Foundation R10503000)>
     NIL
     NIL
     #<FUNCTION (LAMBDA #) {A7DE735}>)[:EXTERNAL]
15: (XLIB::READ-REPLY #<unavailable argument> #<unavailable argument>)
16: (XLIB::QUERY-FONT #<XLIB:FONT 9x15bold :0 6291462>)
17: (XLIB:OPEN-FONT
     #<XLIB:DISPLAY :0 (The X.Org Foundation R10503000)>
     "9x15bold")
18: (STUMPWM::INIT-SCREEN #<XLIB:SCREEN :0.0 1920x1200x24 TRUE-COLOR> 0 "")
19: (STUMPWM::STUMPWM-INTERNAL ":0")
20: (STUMPWM:STUMPWM ":0")
21: (SB-INT:SIMPLE-EVAL-IN-LEXENV (STUMPWM:STUMPWM ":0") #<NULL-LEXENV>)
22: (SB-IMPL::PROCESS-EVAL/LOAD-OPTIONS ((:EVAL . "(stumpwm:stumpwm \":0\")")))
23: (SB-IMPL::TOPLEVEL-INIT)
24: ((LABELS SB-IMPL::RESTART-LISP))

unhandled condition in --disable-debugger mode, quitting