The previous download link only worked for the most recent version. The
new form only works for old versions. That will encourage us not to use
the latest version, but for tests that's probably not a big deal.
We haven't noticed the breakage sooner because the build results are
cached.
Without the attributes, fc loses its mind a bit when comparing the
codegen output against the golden; the golden would have DOS newlines
(assuming default git configuration) and the generated code would have
Unix newlines.
The jenkins-pre script just reduces the amount of code is backed into
the jenkins project.