How can I uniquely identify a build?

[Jamie Ide]

To my surprise and consternation, Bamboo's build numbers are not globally unique like TeamCity's are. How can I uniquely identify a build so that I can set that value in the build position of my version number (1.2.3.build)? There are a variety of variables I could use but many of those could change if a plan or job was renamed.

I've currently settled on a concatenation of the build number and the first seven characters of the git hash. To get there, I have to read the base version from a file, write it back with the build number, write it to a file, then import it using the import variables task so that it is available to later tasks. There's got to be a better way.