The Alternative Git Chooser plugin is not working correctly when the branch specifier is using a macro, e.g. a build parameter. Steps to reproduce:

1. Add a build parameter, e.g. BRANCH.
2. Set the first Git branch specifier to ${BRANCH}.
3. Set the second Git branch specifier to a valid branch, e.g. master.
4. Start a build and set the BRANCH parameter value to any valid branch other than the one specified in step # 3.
5. It will still starting building the branch specified in step # 3.

The issue does not occur when you enter a valid branch, other than the one specified in step # 3, directly as the first branch specifier. This leads me to suspect that maybe the Alternative Git Chooser plugin is not properly expanding macros when it is iterating over the branch specifiers.