Git - Get a code/version identifier for use in log

Question

We run lots of benchmarks against our code as we iterate. These benchmarks are logged and timestamped. But, it's not obvious from the timestamp which version of the code was invoked.

We'd like to have git generate an identifier of the particular version, and have this identifier appear in our log output.

A few challenges:

• Ideally, the identifier should show not only the id of the last checkin, but also, if any files have been modified or added but not checked in, the timestamp of the last modification that has not yet been checked in. This lets us track different code versions that haven't yet been checked in.
• Our code is C, so it's compiled, so we need git to somehow output the results during the build process.

Answer 1

• Benchmarking of uncommited code is The Bad Idea (tm)
• Git describe is the easiest way to get unique identification for any and every changeset