Gradle not recognizing configuration?

I’m getting the following error when I’m trying to build my project:

Caused by: java.lang.RuntimeException: Module version foo-SNAPSHOT, configuration ‘detachedConfiguration16’ declares a dependency on configuration ‘default’ which is not declared in the module descriptor for barversion

But in my gradle file i have:

compile group: ‘group’, name: ‘bar’, version: version, configuration: ‘compile’

and in 'bar’s ivy.xml it has:

<conf name="compile"/>
<conf name="runtime"/>

The odd thing to me is that this exact syntax for the dependency is working in another project, and if I change the configuration to say ‘bob’ I get an error about bob, but if I change it to ‘compile’ I only get the error about default? Any ideas?