A dependency on configuration 'default'

The problem is that “default” is a keyword in Groovy (and Java).

You can use the following code:

dependencies {
  it."default"
}

This works because

dependencies {
  default
}

Is the same as:

dependencies.default

When you use the closure version, the ‘dependencies’ object is passed to the closure as the implicit argument, and Groovy supports using strings as property names for situations like this (and others).