It failed with the error shown in [this build log](https://launchpadlibrarian.net/293528368/buildlog_ubuntu-trusty-amd64.geany-...).
The error is pretty straightforward: GitChangebar plugin is force-enabled (`--enable-gitchangebar`), but one of its dependencies is missing:
Requested 'libgit2 >= 0.21' but version of libgit2 is 0.19.0
Either don't build this plugin, or use a recent enough version of libgit2.