buildFiles

@get:InputFiles
@get:PathSensitive(value = PathSensitivity.RELATIVE)
abstract val buildFiles: ConfigurableFileCollection(source)

The subproject build files themselves, scanned to locate the line each project dependency is declared on (DependencyEdge.declarationLine).

Declared as an input because their contents change the output: reordering two dependency declarations changes the recorded lines without changing any other input, and a cached run would otherwise report stale line numbers. RELATIVE path sensitivity keeps the task relocatable across checkout directories.