对SBCL中的``ql:quickload``和可执行脚本感到困惑

我一直在尝试在我的可执行脚本中使用Quicklisp包.一个(平凡的)工作示例是:

#!/usr/bin/sbcl --script

(eval-when (:compile-toplevel :load-toplevel :execute)
  (ql:quickload "lisp-unit")) ;as explained by another question

(defpackage :test
  (:use :cl :lisp-unit))

(format t "This is a test.")

在chmod使用此代码(调用test.lisp)的文件后,我尝试执行它.但是,我收到以下错误消息:

Unhandled SB-C::INPUT-ERROR-IN-LOAD in thread #:
  READ error during LOAD:

    Package QL does not exist.

      Line: 4, Column: 15, File-Position: 95

      Stream: #

Backtrace for: #
0: ((LAMBDA NIL :IN SB-DEBUG::FUNCALL-WITH-DEBUG-IO-SYNTAX))
1: (SB-IMPL::CALL-WITH-SANE-IO-SYNTAX #)
2: (SB-IMPL::%WITH-STANDARD-IO-SYNTAX #)
3: (PRINT-BACKTRACE :STREAM # :START 0 :FROM :INTERRUPTED-FRAME :COUNT NIL :PRINT-THREAD T :PRINT-FRAME-SOURCE NIL :METHOD-FRAME-STYLE NIL)
4: (SB-DEBUG::DEBUGGER-DISABLED-HOOK # #)
5: (SB-DEBUG::RUN-HOOK *INVOKE-DEBUGGER-HOOK* #)
6: (INVOKE-DEBUGGER #)
7: (ERROR #)
8: (SB-C:COMPILER-ERROR SB-C::INPUT-ERROR-IN-LOAD :CONDITION # :STREAM #)
9: (SB-C::READ-FOR-COMPILE-FILE # 25 SB-C::INPUT-ERROR-IN-LOAD)
10: (SB-INT:LOAD-AS-SOURCE # :VERBOSE NIL :PRINT NIL :CONTEXT "loading")
11: ((FLET SB-FASL::LOAD-STREAM :IN LOAD) # NIL)
12: (LOAD # :VERBOSE NIL :PRINT NIL :IF-DOES-NOT-EXIST T :EXTERNAL-FORMAT :DEFAULT)
13: ((FLET SB-IMPL::LOAD-SCRIPT :IN SB-IMPL::PROCESS-SCRIPT) #)
14: ((FLET #:WITHOUT-INTERRUPTS-BODY-140 :IN SB-IMPL::PROCESS-SCRIPT))
15: (SB-IMPL::PROCESS-SCRIPT "./test.lisp")
16: (SB-IMPL::TOPLEVEL-INIT)
17: ((FLET #:WITHOUT-INTERRUPTS-BODY-89 :IN SAVE-LISP-AND-DIE))
18: ((LABELS SB-IMPL::RESTART-LISP :IN SAVE-LISP-AND-DIE))

unhandled condition in --disable-debugger mode, quitting

我不确定这里发生了什么 - 如果我尝试从顶层做类似的事情(即,启动SBCL,加载lisp-unit使用ql:quickload等),我不会得到这样的东西.