grails-mondrian 0.3 does not install

Run these commands:

grails create-app mbug
cd mbug
grails install-plugin mondrian

I get this error:

C:\dev\grails-proj\mbug>grails install-plugin mondrian
Welcome to Grails 1.3.7 - http://grails.org/
Licensed under Apache Standard License 2.0
Grails home is set to: c:\dev\grails-1.3.7

Base Directory: C:\dev\grails-proj\mbug
Resolving dependencies...
Dependencies resolved in 827ms.
Running script c:\dev\grails-1.3.7\scripts\InstallPlugin.groovy
Environment set to development
Resolving plugin mondrian. Please wait...

Installing zip C:\Users\cmaeda\.ivy2\cache\org.grails.plugins\mondrian\zips\mond
rian-0.3.zip... ...
[mkdir] Created dir: C:\Users\cmaeda\.grails\1.3.7\projects\mbug\plugins\mon
drian-0.3
[unzip] Expanding: C:\Users\cmaeda\.ivy2\cache\org.grails.plugins\mondrian\z
ips\mondrian-0.3.zip into C:\Users\cmaeda\.grails\1.3.7\projects\mbug\plugins\mo
ndrian-0.3
Installed plugin mondrian-0.3 to location C:\Users\cmaeda\.grails\1.3.7\projects
\mbug\plugins/mondrian-0.3. ...
Resolving plugin JAR dependencies ...
Executing mondrian-0.3 plugin post-install script ...
[mkdir] Created dir: C:\dev\grails-proj\mbug\web-app\jpivot
[copy] Copying 105 files to C:\dev\grails-proj\mbug\web-app\jpivot
[mkdir] Created dir: C:\dev\grails-proj\mbug\web-app\wcf
[copy] Copying 60 files to C:\dev\grails-proj\mbug\web-app\wcf
Error installing plugin: C:\Users\cmaeda\.grails\1.3.7\projects\mbug\plugins\mon
drian-0.3\web-app\WEB-INF not found.
[delete] Deleting directory C:\Users\cmaeda\.grails\1.3.7\projects\mbug\plugi
ns\mondrian-0.3

Error seems to be caused by this code in scripts/_Install.groovy:

Ant.copy(todir:"$

/web-app/WEB-INF") {
fileset(dir:"$

/web-app/WEB-INF")
}

If I comment this line out, the plugin installs ok.