[Boost-build] How to use alias?

Subject: [Boost-build] How to use alias?
From: áÌÅËÓÅÊ îÉËÉÔÉÎ (alleonik_at_[hidden])
Date: 2010-10-03 08:54:44

 Hi.

In documenation write what alias rule may be used for change build
properties, but next code fail after command "bjam a_p a_r":

lib a.lib : a.cpp ;
alias a_p.lib : a.lib : <variant>profile ;
alias a_r.lib : a.lib : <variant>release ;
install a_p : a_p.lib : <location>. ;
install a_r : a_r.lib : <location>. ;

with message

C:/Work/boost_1_44_0/tools/build/v2/build\virtual-target.jam:1066: in
virtual-target.register-actual-name from module virtual-target
error: Duplicate name of actual target: <p.>a.dll
error: previous virtual target { common%common.copy-a.dll.SHARED_LIB {
msvc%msvc.link.dll-a.dll.SHARED_LIB { msvc%msvc.compile.c++-a.obj.OBJ {
a.cpp.CPP } } } }
error: created from ./a_r
error: another virtual target { common%common.copy-a.dll.SHARED_LIB {
msvc%msvc.link.dll-a.dll.SHARED_LIB { msvc%msvc.compile.c++-a.obj.OBJ {
a.cpp.CPP } } } }
error: created from ./a_p
error: added properties: <debug-symbols>on <profiling>on <variant>profile
error: removed properties: <debug-symbols>off <profiling>off
<variant>release
C:/Work/boost_1_44_0/tools/build/v2/build\virtual-target.jam:490: in
actualize-no-scanner from module object(file-target)@104
C:/Work/boost_1_44_0/tools/build/v2/build\virtual-target.jam:135: in
object(file-target)@104.actualize from module object(file-target)@104
C:/Work/boost_1_44_0/tools/build/v2\build-system.jam:748: in load from
module build-system
C:\Work\test_bb2\..\boost_1_44_0\tools\build\v2/kernel\modules.jam:283: in
import from module modules
C:\Work\test_bb2\..\boost_1_44_0\tools\build\v2\kernel\bootstrap.jam:142: in
boost-build from module
C:\Work\test_bb2\boost-build.jam:1: in module scope from module

Origianl task is to install target with several build properties in own
location. How I can change code for that task?
And is it possible to disable build a.lib directly (whitout properties)?