So here we go again ... this time using native Smalltalk code to describe package contents in a DRY way:

Eval [
  PackageBuilder new
    name: 'MyPackage';
    namespace: 'MyNamespace';
    prereq: 'Package1';
    prereq: 'Package2';
    ...
    testsBelow: 'Tests' matching: '*.st';
    filein: 'File1.st';
    filein: 'File2.st';
    ...
    buildXml
]