git describe fails with "fatal: No names found, cannot describe anything."

Question

I'm using git 1.7.1 on Ubuntu 10.10 amd64, and I'm trying to extract the hash of my repository HEAD to use it in an automated version information that I compile into my project.

In the past, this always worked by using

git describe --tags

however, git is now throwing

fatal: No names found, cannot describe anything.

at me. Does anyone have a clue what that means?

Google showed only few hits and no solution.

Answer 1

If you want the id of your HEAD then you don't need describe, you should just use rev-parse.

git rev-parse HEAD

If you want an abbreviated hash you can use --short.

git rev-parse --short HEAD

If you want a "describe" to fall back to an abbreviated hash if it can't find any suitable tags, you can use --always.

git describe --always