code: def get_git_version(fallback):
      def format_version(release, is_dev, labels):
          dev = ".dev0" if is_dev else ""
          labels = "+" + ".".join(labels) if labels else ""
          return "".join([release, dev, labels])
  
      dist_root_ = dist_root()
      repo = GitRepo(dist_root_)
  
      try:
          # TODO: Do we really need this check?
          if repo.root() != dist_root_:
              return None
      except (subprocess.CalledProcessError, FileNotFoundError):
          # can fail if git is not installed, or command fails
          return None
  
      try:
          git_tag = repo.describe()
          release, num_changes, git_hash = git_tag.rsplit("-", 2)
  
          release = release.lstrip("v")
          # if the current commit is not tagged directly, num_changes is ` > 0`
          # and attach the `.dev` label
          is_dev = num_changes != "0"
          labels = [git_hash] if is_dev else []
  
      except subprocess.CalledProcessError:
          # If there is no git-tag, we have to fallback.
          release = fallback
          is_dev = False
          labels = ["g" + repo.head_commit()]
  
      if not repo.clean():
          labels.append("dirty")
  
      return format_version(release, is_dev, labels)
  
file_path: gluonts/src/gluonts/meta/_version.py
imports: import os
  import subprocess
  from pathlib import Path
label_desc: Use image node_id 4 for calling a global function with example usage: get_git_version(fallback) and returns: format_version, str, None, None