We have the local subdirectory for repo defined as "${GIT_BRANCH}" – this creates a different subdirectory for every branch being built, allowing us to cache a lot of build objects between builds while keeping separate branches, well, separated.

However, the very first trigger of the build for any given branch fails. It's fine after that; as in, works fine after a second push to our git repo (which then hits Jenkins via github's webhook API).

Any thoughts as to what's causing this?

Thanks!
-Jeff