Re: `git describe` in an export-subst format string?

John Gallagher [off-list ref] writes:

The actual thing I want to do is
something like this:

  static const char *project_version = "$Format:...$";

where "..." is something that `git archive` will replace with the
output of `git describe`,...

You need to find an appropriate pair of placeholders that can
represent "git describe $it" and "git describe --contains $it".

I am tempted to suggest a more generalized way that is not limited
to describe at all, perhaps like this:

    $ git show --format='%x( git describe %H )'
    $ git show --format='%x( git describe --contains %H )'