[Omake] scanners not considered valid targets by "target-is-proper"?

[Erick Tryzelaar]

I was playing around with target-is-proper, and it appears to not work 
for scanners. Is there a reason for this? Here's a demonstration of the 
problem:

% .SCANNER: baz: bar
rule>     .SCANNER: baz: bar
rule>        echo hi
rule>        .
.
- : <rules:
        rule {
           target = <scanner 
/unencrypted/erickt/Projects/omake/omake_newbuild/baz>
           effects = <scanner 
/unencrypted/erickt/Projects/omake/omake_newbuild/baz>
           locks =
           sources = /unencrypted/erickt/Projects/omake/omake_newbuild/bar
           scanners =
           commands =
              {
                 command_dir = 
/unencrypted/erickt/Projects/omake/omake_newbuild;
                 command_sources = 
/unencrypted/erickt/Projects/omake/omake_newbuild/bar
                 command_body = "echo hi" : Sequence
              }
        }>
% echo $(target-is-proper baz)
false


Normal rules work though:

% foo: bar
rule>     foo: bar
rule>        echo hi
rule>        .
.
- : <rules:
        rule {
           target = /unencrypted/erickt/Projects/omake/omake_newbuild/foo
           effects = /unencrypted/erickt/Projects/omake/omake_newbuild/foo
           locks =
           sources = /unencrypted/erickt/Projects/omake/omake_newbuild/bar
           scanners =
           commands =
              {
                 command_dir = 
/unencrypted/erickt/Projects/omake/omake_newbuild;
                 command_sources = 
/unencrypted/erickt/Projects/omake/omake_newbuild/bar
                 command_body = "echo hi" : Sequence
              }
        }>
% echo $(target-is-proper foo)
true