Setup:

• Git Plugin 1.1.20
• a parameterized build with parameter "Branch", default "**"
• Git SCM with branch specifier "${Branch}"
• SCM polling activated

Intended behaviour:

• if any branch changes, Jenkins checks out and builds this branch
• when executed manually, the user enters the name of the branch to be built

Actual behaviour:

• no changes are detected (because the "${Branch}" value isn't resolved when polling)