对，所以这是一个更复杂的事情，我来到了一个讨厌的变通方案-但是，总比没有好。这里有几个问题-首先，让我们看看子文件夹项目的Jamroot;我会把这个作为一个差异：

diff --git a/projects/qtclient/Jamroot b/projects/qtclient/Jamroot
index 2379580db..d72e3edb5 100644
--- a/projects/qtclient/Jamroot
+++ b/projects/qtclient/Jamroot
@@ -1,6 +1,13 @@
-REDEMPTION_PUBLIC_PATH ?= [ SHELL "readlink -n -f ../.." ] ;
+#REDEMPTION_PUBLIC_PATH ?= [ SHELL "readlink -n -f ../.." ] ;
 
-ECHO "redemption-src: $(REDEMPTION_PUBLIC_PATH)" ;
+path-constant MYPATH : . ;
+REDEMPTION_PUBLIC_PATH ?= [ SHELL "readlink -n -f $(MYPATH)/../.." ] ;
+
+ECHO "qtclient Jamroot: MYPATH $(MYPATH)" ;
+ECHO "qtclient Jamroot: REDEMPTION_ROOT_PATH $(REDEMPTION_ROOT_PATH:E=not_set)" ;
+ECHO "qtclient Jamroot: REDEMPTION_PUBLIC_PATH $(REDEMPTION_PUBLIC_PATH)" ;
+ECHO "qtclient Jamroot: .all-features $(.all-features:E=not_set)" ;
+#ECHO [ SHELL "pstree -s -p $$ && echo PID $$ PWD $PWD" ] ;
 
 JAM_INCLUDE_PATH ?= $(REDEMPTION_PUBLIC_PATH)/jam ;
 REDEMPTION_INCLUDE_PATH ?= $(REDEMPTION_PUBLIC_PATH)/include ;
@@ -124,7 +131,7 @@ add_obj graphics.o : src/qt_input_output_api/graphics.cpp ;
 
 local requirement_list = ;
 # generated by `bjam targets.jam` from redemption project
-include redemption_deps.jam ;
+include $(MYPATH)/redemption_deps.jam ;
 
 
 constant EXE_DEPENDENCIES :

最初，它试图通过[ SHELL "readlink -n -f ../.." ] ;找到REDEMPTION_PUBLIC_PATH-如果用readlink -f ../..调用shell，它别无选择，只能引用它的CWD;它不“知道”它是否在项目的子文件夹中。幸运的是，原来有一个bjam语法可以让jam文件找到自己的路径：path-constant规则（boost-build/bjam constant for path to Jamroot），也就是上述更改所使用的规则，以提供对_INCLUDE_PATH s和include d文件的正确引用-这将消除“ERROR：模块”“中的规则“setvar””未知。
完成后，* 下一个 * 问题是，如果从主Jamfile调用子文件夹项目的构建（例如，通过build-project），我们将得到一个新的错误：

/usr/share/boost-build/src/build/feature.jam:140: in feature from module feature
error: feature already defined:
error: in feature declaration:
error: feature "<cxx-color>" : "_" "default" "auto" "never" "always" : "propagated"

问题是主项目和子项目都做include $(JAM_INCLUDE_PATH)/cxxflags.jam ;等;我试着从子项目Jamroot中手动删除这些内容，因为构建是从主文件夹开始的-但最终我们遇到了子项目Jam，抱怨未知的内容：

/usr/share/boost-build/src/kernel/modules.jam:107: in modules.call-in
ERROR: rule "Jamfile</home/USER/src/redemption.git/projects/qtclient>.flags" unknown in module "Jamfile</home/USER/src/redemption.git/projects/qtclient>".

...所以它仍然需要那些文件，但是它们已经冲突了...所以这种方式行不通。
因此，我们必须再次回到“更改目录”，显然我们必须从shell执行此操作...因此，这部分位于主Jamroot中，再次显示为diff：

diff --git a/Jamroot b/Jamroot
index eb4188fdd..e4a756002 100644
--- a/Jamroot
+++ b/Jamroot
@@ -46,6 +46,27 @@ JAM_INCLUDE_PATH ?= jam ;
 #
 #############################
 
+path-constant REDEMPTION_ROOT_PATH : . ;
+ECHO "main: REDEMPTION_ROOT_PATH $(REDEMPTION_ROOT_PATH)" ;
+import modules ;
+tbuildcmd = "" ;
+local args = [ modules.peek : ARGV ] ;
+if clean in $(args)
+{
+  tbuildcmd = clean ;
+}
+else if release in $(args)
+{
+  tbuildcmd = release ;
+}
+else if debug in $(args)
+{
+  tbuildcmd = debug ;
+}
+echo "tbuildcmd $(tbuildcmd)" ;
+echo "ARGV: $(args)" ;
+echo "INSTALLDIR/BINPREFIX: $(INSTALLDIR:E=not_set)$(BIN_PREFIX:E=not_set)" ;
+
 include $(JAM_INCLUDE_PATH)/redemption-config.jam ;
 include $(JAM_INCLUDE_PATH)/cxxflags.jam ;
 include $(JAM_INCLUDE_PATH)/defines.jam ;
@@ -154,10 +175,22 @@ alias install :
     install-etc-ppocr
     install-share
     install-gettext
+    install-qtclient
 ;
 alias exe     : rdpproxy rdpclient rdpinichecker ;
 alias libs    : libredrec ;
 
+import notfile ;
+notfile post_qtclient : @my-post-command : libs exe ;
+actions my-post-command
+{
+    echo my-post-command $(tbuildcmd) runs.
+    cd projects/qtclient ;
+    bjam $(tbuildcmd) ;
+    cd ../.. ;
+    rsync -aP projects/qtclient/bin/gcc-9/$(tbuildcmd)/. bin/gcc-9/$(tbuildcmd)/
+}
+
 alias ocr_tools : display_learning extract_text ppocr_extract_text ;
 
 alias install-etc-ppocr : install-etc-ppocr-latin install-etc-ppocr-latin-cyrillic ;
@@ -199,6 +232,39 @@ install install-lib
     : <location>$(INSTALLDIR)$(LIB_PREFIX)
     ;
 
+import path : basename ;
+
+#epath = "$(REDEMPTION_ROOT_PATH)/projects/qtclient/bin/gcc-9/release/qt5client" ;
+#ename = basename ( $(epath) ) ; # nope, causes target to not be found :(
+# adds newline at end
+#ename = [ SHELL "basename $(epath)" ] ;
+#ename = SHELL "basename $(epath)" ; # does not work
+actions make_qtclient_install
+{
+    echo "make_qtclient_install: REDEMPTION_ROOT_PATH $(REDEMPTION_ROOT_PATH) PWD $(PWD:E=not_set)" ;
+    echo [ SHELL "pstree -s -p $$ && echo PID $$ PWD $PWD" ] ;
+    # unfortunately, when we get here, bjam is not called with debug or release, so tbuildcmd is empty
+    # so assuming we delete our directories manually:
+    # rm -rf bin/gcc-9/* projects/qtclient/bin/gcc-9/* debian/* ./bin/project-cache.jam ./projects/qtclient/bin/project-cache.jam
+    # we can count on only one qt5client being built in qtclient bin dir, so target it with wildcards
+    # also, debian/buildtmp/usr/local/bin/ $(INSTALLDIR)$(BIN_PREFIX)/ might not exist at this time
+    # so use install instead of cp
+    # don't use local here, crashes "not in a function"
+    # cannot get the stupid glob to work, write manually
+    #epath = [ glob "$(REDEMPTION_ROOT_PATH)/projects/qtclient/bin/gcc-9/*/qt*client" ] ;
+    #epath="$(REDEMPTION_ROOT_PATH)/projects/qtclient/bin/gcc-9/release/qt5client" ;
+    #ename = [ SHELL "basename $(epath)" ] ;
+    #ename=`basename $(epath)`
+    # don't bother with variables, nothing works here https://stackoverflow.com/questions/75342602/bjam-cannot-assign-a-literal-to-a-variable
+    #echo "epath $(epath) ename $(ename)" ;
+    #cp -av $(REDEMPTION_ROOT_PATH)/projects/qtclient/bin/gcc-9/*/qt*client $(INSTALLDIR)$(BIN_PREFIX)/ ;
+    # just type everything verbatim:
+    echo install -m 775 -D $(REDEMPTION_ROOT_PATH)/projects/qtclient/bin/gcc-9/release/qt5client $(INSTALLDIR)$(BIN_PREFIX)/qt5client ;
+    install -m 775 -D $(REDEMPTION_ROOT_PATH)/projects/qtclient/bin/gcc-9/release/qt5client $(INSTALLDIR)$(BIN_PREFIX)/qt5client ;
+}
+explicit install-qtclient ;
+make install-qtclient : : @make_qtclient_install ;
+
 
 exe redrec
 :

首先，我们想知道我们是在做调试还是发布构建;显然在bjam中这是一个“变体”，也是一种“特性”，我不知道如何读取它（Getting the build type/variant inside a bjam Jamfile / echo a feature?），所以我做了一个变通方案，使用命令行参数-当然，只有当你使用bjam命令，并在命令行中显式地包含debug或release时，这才是好的。
然后，notfile被用来定义类似于新的、自定义/手动目标的功能--在某种意义上，我们可以调用post_qtclient，它将触发libs和exe作为依赖项的构建;然后运行my-post-command操作。此操作中的命令在shell中运行，因此我们可以将目录更改为子文件夹project，在debug或release（通过变量）中运行bjam，完成后，将子文件夹project bin目录中的所有文件复制到主bin目录。
这对于通过bjam -a release post_qtclient进行构建来说已经足够了--但是如果您打算运行debhelper脚本来构建一个.deb包（通过这个库中的一个工具./tools/packager.py --build-package --force-build来完成），这就不够了。
为此，我们必须将生成的子文件夹的可执行文件复制到正确的 install 位置;这是通过install-qtclient“make”操作完成的（或者不管是什么）。在那里处理字符串是非常棘手的（留下注解以记录这一点）-所以最后，这一部分将硬编码的子文件夹项目可执行文件复制到“bin”安装位置，就像其他可执行文件一样-然而，使用X1 M22 N1 X，因为在这一块运行时，您访问的页面不存在！
这通常会注意到安装部分;最后要确保子项目的可执行文件最终保存在.deb文件中，请按如下方式更改/packaging/template/debian/rules：

diff --git a/packaging/template/debian/rules b/packaging/template/debian/rules
index 014c470e4..dab9a70ea 100755
--- a/packaging/template/debian/rules
+++ b/packaging/template/debian/rules
@@ -32,7 +32,8 @@ build:
        # dh_testdir - test directory before building Debian package. It makes sure
        # that debian/control exists also check Jamroot for redemption project.
        dh_testdir Jamroot
-       bjam -q $(BJAM_EXTRA_INSTALL) exe libs
+       #bjam -q $(BJAM_EXTRA_INSTALL) exe libs
+       bjam -q $(BJAM_EXTRA_INSTALL) post_qtclient

...这最终会生成一个.deb文件，该文件中的子项目可执行文件与此过程的其他可执行文件位于同一个bin文件夹中。
请注意，由于缓存的原因，从头开始重建项目可能会很棘手，所以我在这里执行了以下命令来“清理所有内容”：

rm -rf bin/gcc-9/* projects/qtclient/bin/gcc-9/* debian/* ./bin/project-cache.jam ./projects/qtclient/bin/project-cache.jam

好吧，希望这就是问题所在...