get_git_version

#!/bin/bash
set -eEu -o pipefail
trap 'echo "$0: line $LINENO: exit code $?" >&2' ERR
this=${BASH_SOURCE[0]}
while [ -h "$this" ]; do this=$(readlink "$this"); done

version_file=$(dirname "$this")/GIT_VERSION
if [ -r "$version_file" ]; then
    version=$(cat "$version_file")
else
    version="missing_git_version"
fi

git describe --always 2>/dev/null || echo "$version"