[Boost-build] Notfile rule results in duplicate name of actual target

Subject: [Boost-build] Notfile rule results in duplicate name of actual target
From: John Bito (jwbito_at_[hidden])
Date: 2009-08-10 23:00:10

This 'duplicate name of target' message is really becoming bothersome.
 I'm really curious about the sequence of messages I get when I do
something like:

notfile always1 : @do-nothing ;
make vernum.c : always1 : @write-version : <version-text>$(INFO) ;
obj vernum : vernum.c ;

As you may guess, I'm trying to produce source file containing
version/config info at each build.  It's confounding that the notfile
target is triggering the 'duplicate name' error, particularly since
appears only as a dependency of the obj.  The error messages are
listed below.  Those messages don't appear if I remove the dependency
on always1, but (of course) the vernum.c file is only created if I
delete it.  (I can also get a bunch of targets dependent on the above
to work - I can't tell yet which dependent targets trigger the
problem.)

Thanks for any guidance!
John
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:1032: in
virtual-target.register-actual-name
warning: rulename $(cs1).main-target expands to empty string
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:480: in
actualize-no-scanner
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:130: in
object(notfile-target)@7920.actualize
/home/jbito/workspace/SVN-Boost/v2/build-system.jam:713: in load
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/modules.jam:283: in import
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/bootstrap.jam:142: in
boost-build
/home/jbito/workspace/ads/boost-build.jam:1: in module scope
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:1033: in
virtual-target.register-actual-name
warning: rulename $(cs2).main-target expands to empty string
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:480: in
actualize-no-scanner
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:130: in
object(notfile-target)@7920.actualize
/home/jbito/workspace/SVN-Boost/v2/build-system.jam:713: in load
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/modules.jam:283: in import
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/bootstrap.jam:142: in
boost-build
/home/jbito/workspace/ads/boost-build.jam:1: in module scope
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:1052: in
virtual-target.register-actual-name
warning: rulename $(cmt1).full-name expands to empty string
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:480: in
actualize-no-scanner
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:130: in
object(notfile-target)@7920.actualize
/home/jbito/workspace/SVN-Boost/v2/build-system.jam:713: in load
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/modules.jam:283: in import
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/bootstrap.jam:142: in
boost-build
/home/jbito/workspace/ads/boost-build.jam:1: in module scope
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:1054: in
virtual-target.register-actual-name
warning: rulename $(cmt2).full-name expands to empty string
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:480: in
actualize-no-scanner
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:130: in
object(notfile-target)@7920.actualize
/home/jbito/workspace/SVN-Boost/v2/build-system.jam:713: in load
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/modules.jam:283: in import
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/bootstrap.jam:142: in
boost-build
/home/jbito/workspace/ads/boost-build.jam:1: in module scope
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:1056: in
virtual-target.register-actual-name from module virtual-target
error: Duplicate name of actual target:
<l./sun/debug/architecture-sparc/instruction-set-v9>always1
error: previous virtual target {
Jamfile</home/jbito/workspace/ads/ADS>%Jamfile</home/jbito/workspace/ads/ADS>.do-nothing1-always1.
}
error: created from
error: another virtual target {
Jamfile</home/jbito/workspace/ads/ADS>%Jamfile</home/jbito/workspace/ads/ADS>.do-nothing1-always1.
}
error: created from
error: added properties: none
error: removed properties: none
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:480: in
actualize-no-scanner from module object(notfile-target)@7920
/home/jbito/workspace/SVN-Boost/v2/build/virtual-target.jam:130: in
object(notfile-target)@7920.actualize from module
object(notfile-target)@7920
/home/jbito/workspace/SVN-Boost/v2/build-system.jam:713: in load from
module build-system
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/modules.jam:283: in
import from module modules
/home/jbito/workspace/ads/../SVN-Boost/v2/kernel/bootstrap.jam:142: in
boost-build from module
/home/jbito/workspace/ads/boost-build.jam:1: in module scope from module