git describe --tags --long adds character to hash? [duplicate]

Question

git rev-parse --short HEAD outputs:

6aa3158a

git describe --tags --long outputs:

2.3.4-rck1-0-g6aa3158a

I see that the latter command adds a g to the commit hash. Why is this?

Answer 1

From man git-describe:

The "g" prefix stands for "git" and is used to allow describing the version of a software depending on the SCM the software is managed with. This is useful in an environment where people may use different SCMs.

Answer 2

That is the documented behavior of --longaccording to git-describe(1):

   --long
       Always output the long format (the tag, the number of commits and
       the abbreviated commit name) even when it matches a tag. This is
       useful when you want to see parts of the commit object name in
       "describe" output, even when the commit in question happens to be a
       tagged version. Instead of just emitting the tag name, it will
       describe such a commit as v1.2-0-gdeadbee (0th commit since tag
       v1.2 that points at object deadbee....).

And later on in the same document is an explanation for why it adds the g prefix to the hash:

The "g" prefix stands for "git" and is used to allow describing the version of a software depending on the SCM the software is managed with. This is useful in an environment where people may use different SCMs.