I have an MSBuild `ItemGroup` and I would like to be able to `echo` it out in the "Post-Build Event".

However when I try commands like: `echo My ItemGroup: @(Foo)`

I get the error:

> 
> error MSB4164: The value "echo My ItemGroup: @(Foo)" of metadata "Command" contains an item list expression. Item list expressions are not allowed on default metadata values.
> 
> 
> 

I'm not very good with `ItemGroup`s as of yet. Is there a way I can just `echo` the list of files that `Foo` contains?