我正在尝试构建OS161的用户区。当我在命令行中键入make时，会出现以下错误:

Makefile 24:***缺少分隔符（您是指制表符而不是8个空格吗？）。停下来。

我检查了Makefile的第24行，并尝试在行的开头添加一个制表符，但是没有起作用，因为我随后得到了另一个错误:

生成文件24:***制作方法在第一个目标之前开始。停下来。

下面是完整的makefile以供参考:

#
# Toplevel makefile for OS/161.
#
#
# Main rules:
#    all (default):  depend and compile system; install into staging area
#    rebuild:        likewise, but start with a clean slate.
#    fullrebuild:    likewise, but start with a very clean slate.
#
# What all does, in order:
#    tools:          depend and compile the tools used in build.
#    includes:       install header files.
#    build:          depend and compile the system.
#
# Other targets:
#    depend:         just update make dependency information.
#    tags:           generate/regenerate "tags" files.
#    install:        install into $(OSTREE).
#    clean:          remove generated files.
#    distclean:      remove all generated files.
#

TOP=.
.include "$(TOP)/mk/os161.config.mk"

all:;  # make this first

MKDIRS=$(OSTREE)

.include "$(TOP)/mk/os161.mkdirs.mk"

all: tools .WAIT includes .WAIT build

rebuild:
    $(MAKE) clean
    $(MAKE) all

fullrebuild:
    $(MAKE) distclean
    $(MAKE) all

# currently no tools required, hence no tools/ dir or work to do
tools:
    @true

build:
    (cd userland && $(MAKE) build)
    (cd man && $(MAKE) install-staging)
    (cd testscripts && $(MAKE) build)

includes tags depend:
    (cd kern && $(MAKE) $@)
    (cd userland && $(MAKE) $@)

clean:
    (cd kern && $(MAKE) $@)
    (cd userland && $(MAKE) $@)
    rm -rf $(INSTALLTOP)

distclean: clean
    rm -rf $(WORKDIR)

install: $(OSTREE)
    (cd $(INSTALLTOP) && tar -cf - .) | (cd $(OSTREE) && tar -xvf -)


.PHONY: all rebuild fullrebuild tools build includes tags depend
.PHONY: clean distclean

# old BSD name, same as distclean
cleandir: distclean
.PHONY: cleandir

问题（24）的行是:

.include "$(TOP)/mk/os161.config.mk"

如有任何帮助，我们将不胜感激。我检查了类似的makefile错误，但我似乎找不到哪里出了问题。