Make the library modular usable.

build.jam

@@ -0,0 +1,25 @@
+# Copyright René Ferdinand Rivera Morell 2023
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+import project ;
+
+project /boost/system
+    : common-requirements
+        <source>/boost/assert//boost_assert
+        <source>/boost/config//boost_config
+        <source>/boost/throw_exception//boost_throw_exception
+        <source>/boost/variant2//boost_variant2
+        <source>/boost/winapi//boost_winapi
+        <include>include
+    ;
+
+explicit
+    [ alias boost_system : build//boost_system ]
+    [ alias all : boost_system test ]
+    ;
+
+call-if : boost-library system
+    : install boost_system
+    ;

build/Jamfile.v2

@@ -7,7 +7,7 @@
 
 # See library home page at https://www.boost.org/libs/system
 
-project boost/system
+project
     : source-location ../src
     : usage-requirements  # pass these requirement to dependents (i.e. users)
       <link>shared:<define>BOOST_SYSTEM_DYN_LINK=1
@@ -21,5 +21,3 @@ lib boost_system
    : <link>shared:<define>BOOST_SYSTEM_DYN_LINK=1
      <link>static:<define>BOOST_SYSTEM_STATIC_LINK=1
    ;
-
-boost-install boost_system ;

test/Jamfile.v2

@@ -17,6 +17,8 @@ project
 
   : requirements
 
+    <source>/boost/core//boost_core
+
     <toolset>msvc:<warnings-as-errors>on
     <toolset>gcc:<warnings-as-errors>on
     <toolset>clang:<warnings-as-errors>on